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  <div class="section" id="module-urllib.request">
<span id="urllib-request-extensible-library-for-opening-urls"></span><h1>21.6. <a class="reference internal" href="#module-urllib.request" title="urllib.request: Extensible library for opening URLs."><code class="xref py py-mod docutils literal"><span class="pre">urllib.request</span></code></a> — Extensible library for opening URLs<a class="headerlink" href="#module-urllib.request" title="Permalink to this headline">¶</a></h1>
<p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.6/Lib/urllib/request.py">Lib/urllib/request.py</a></p>
<hr class="docutils" />
<p>The <a class="reference internal" href="#module-urllib.request" title="urllib.request: Extensible library for opening URLs."><code class="xref py py-mod docutils literal"><span class="pre">urllib.request</span></code></a> module defines functions and classes which help in
opening URLs (mostly HTTP) in a complex world — basic and digest
authentication, redirections, cookies and more.</p>
<div class="admonition seealso">
<p class="first admonition-title">See also</p>
<p class="last">The <a class="reference external" href="http://docs.python-requests.org/">Requests package</a>
is recommended for a higher-level HTTP client interface.</p>
</div>
<p>The <a class="reference internal" href="#module-urllib.request" title="urllib.request: Extensible library for opening URLs."><code class="xref py py-mod docutils literal"><span class="pre">urllib.request</span></code></a> module defines the following functions:</p>
<dl class="function">
<dt id="urllib.request.urlopen">
<code class="descclassname">urllib.request.</code><code class="descname">urlopen</code><span class="sig-paren">(</span><em>url</em>, <em>data=None</em>, <span class="optional">[</span><em>timeout</em>, <span class="optional">]</span><em>*</em>, <em>cafile=None</em>, <em>capath=None</em>, <em>cadefault=False</em>, <em>context=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.urlopen" title="Permalink to this definition">¶</a></dt>
<dd><p>Open the URL <em>url</em>, which can be either a string or a
<a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> object.</p>
<p><em>data</em> must be an object specifying additional data to be sent to the
server, or <code class="docutils literal"><span class="pre">None</span></code> if no such data is needed.  See <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a>
for details.</p>
<p>urllib.request module uses HTTP/1.1 and includes <code class="docutils literal"><span class="pre">Connection:close</span></code> header
in its HTTP requests.</p>
<p>The optional <em>timeout</em> parameter specifies a timeout in seconds for
blocking operations like the connection attempt (if not specified,
the global default timeout setting will be used).  This actually
only works for HTTP, HTTPS and FTP connections.</p>
<p>If <em>context</em> is specified, it must be a <a class="reference internal" href="ssl.html#ssl.SSLContext" title="ssl.SSLContext"><code class="xref py py-class docutils literal"><span class="pre">ssl.SSLContext</span></code></a> instance
describing the various SSL options. See <a class="reference internal" href="http.client.html#http.client.HTTPSConnection" title="http.client.HTTPSConnection"><code class="xref py py-class docutils literal"><span class="pre">HTTPSConnection</span></code></a>
for more details.</p>
<p>The optional <em>cafile</em> and <em>capath</em> parameters specify a set of trusted
CA certificates for HTTPS requests.  <em>cafile</em> should point to a single
file containing a bundle of CA certificates, whereas <em>capath</em> should
point to a directory of hashed certificate files.  More information can
be found in <a class="reference internal" href="ssl.html#ssl.SSLContext.load_verify_locations" title="ssl.SSLContext.load_verify_locations"><code class="xref py py-meth docutils literal"><span class="pre">ssl.SSLContext.load_verify_locations()</span></code></a>.</p>
<p>The <em>cadefault</em> parameter is ignored.</p>
<p>This function always returns an object which can work as a
<a class="reference internal" href="../glossary.html#term-context-manager"><span class="xref std std-term">context manager</span></a> and has methods such as</p>
<ul class="simple">
<li><code class="xref py py-meth docutils literal"><span class="pre">geturl()</span></code> — return the URL of the resource retrieved,
commonly used to determine if a redirect was followed</li>
<li><code class="xref py py-meth docutils literal"><span class="pre">info()</span></code> — return the meta-information of the page, such as headers,
in the form of an <a class="reference internal" href="email.parser.html#email.message_from_string" title="email.message_from_string"><code class="xref py py-func docutils literal"><span class="pre">email.message_from_string()</span></code></a> instance (see
<a class="reference external" href="https://www.cs.tut.fi/~jkorpela/http.html">Quick Reference to HTTP Headers</a>)</li>
<li><code class="xref py py-meth docutils literal"><span class="pre">getcode()</span></code> – return the HTTP status code of the response.</li>
</ul>
<p>For HTTP and HTTPS URLs, this function returns a
<a class="reference internal" href="http.client.html#http.client.HTTPResponse" title="http.client.HTTPResponse"><code class="xref py py-class docutils literal"><span class="pre">http.client.HTTPResponse</span></code></a> object slightly modified. In addition
to the three new methods above, the msg attribute contains the
same information as the <a class="reference internal" href="http.client.html#http.client.HTTPResponse.reason" title="http.client.HTTPResponse.reason"><code class="xref py py-attr docutils literal"><span class="pre">reason</span></code></a>
attribute — the reason phrase returned by server — instead of
the response headers as it is specified in the documentation for
<a class="reference internal" href="http.client.html#http.client.HTTPResponse" title="http.client.HTTPResponse"><code class="xref py py-class docutils literal"><span class="pre">HTTPResponse</span></code></a>.</p>
<p>For FTP, file, and data URLs and requests explicitly handled by legacy
<a class="reference internal" href="#urllib.request.URLopener" title="urllib.request.URLopener"><code class="xref py py-class docutils literal"><span class="pre">URLopener</span></code></a> and <a class="reference internal" href="#urllib.request.FancyURLopener" title="urllib.request.FancyURLopener"><code class="xref py py-class docutils literal"><span class="pre">FancyURLopener</span></code></a> classes, this function
returns a <code class="xref py py-class docutils literal"><span class="pre">urllib.response.addinfourl</span></code> object.</p>
<p>Raises <a class="reference internal" href="urllib.error.html#urllib.error.URLError" title="urllib.error.URLError"><code class="xref py py-exc docutils literal"><span class="pre">URLError</span></code></a> on protocol errors.</p>
<p>Note that <code class="docutils literal"><span class="pre">None</span></code> may be returned if no handler handles the request (though
the default installed global <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a> uses
<a class="reference internal" href="#urllib.request.UnknownHandler" title="urllib.request.UnknownHandler"><code class="xref py py-class docutils literal"><span class="pre">UnknownHandler</span></code></a> to ensure this never happens).</p>
<p>In addition, if proxy settings are detected (for example, when a <code class="docutils literal"><span class="pre">*_proxy</span></code>
environment variable like <span class="target" id="index-0"></span><code class="xref std std-envvar docutils literal"><span class="pre">http_proxy</span></code> is set),
<a class="reference internal" href="#urllib.request.ProxyHandler" title="urllib.request.ProxyHandler"><code class="xref py py-class docutils literal"><span class="pre">ProxyHandler</span></code></a> is default installed and makes sure the requests are
handled through the proxy.</p>
<p>The legacy <code class="docutils literal"><span class="pre">urllib.urlopen</span></code> function from Python 2.6 and earlier has been
discontinued; <a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urllib.request.urlopen()</span></code></a> corresponds to the old
<code class="docutils literal"><span class="pre">urllib2.urlopen</span></code>.  Proxy handling, which was done by passing a dictionary
parameter to <code class="docutils literal"><span class="pre">urllib.urlopen</span></code>, can be obtained by using
<a class="reference internal" href="#urllib.request.ProxyHandler" title="urllib.request.ProxyHandler"><code class="xref py py-class docutils literal"><span class="pre">ProxyHandler</span></code></a> objects.</p>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.2: </span><em>cafile</em> and <em>capath</em> were added.</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.2: </span>HTTPS virtual hosts are now supported if possible (that is, if
<a class="reference internal" href="ssl.html#ssl.HAS_SNI" title="ssl.HAS_SNI"><code class="xref py py-data docutils literal"><span class="pre">ssl.HAS_SNI</span></code></a> is true).</p>
</div>
<div class="versionadded">
<p><span class="versionmodified">New in version 3.2: </span><em>data</em> can be an iterable object.</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.3: </span><em>cadefault</em> was added.</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4.3: </span><em>context</em> was added.</p>
</div>
<div class="deprecated">
<p><span class="versionmodified">Deprecated since version 3.6: </span><em>cafile</em>, <em>capath</em> and <em>cadefault</em> are deprecated in favor of <em>context</em>.
Please use <a class="reference internal" href="ssl.html#ssl.SSLContext.load_cert_chain" title="ssl.SSLContext.load_cert_chain"><code class="xref py py-meth docutils literal"><span class="pre">ssl.SSLContext.load_cert_chain()</span></code></a> instead, or let
<a class="reference internal" href="ssl.html#ssl.create_default_context" title="ssl.create_default_context"><code class="xref py py-func docutils literal"><span class="pre">ssl.create_default_context()</span></code></a> select the system’s trusted CA
certificates for you.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="urllib.request.install_opener">
<code class="descclassname">urllib.request.</code><code class="descname">install_opener</code><span class="sig-paren">(</span><em>opener</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.install_opener" title="Permalink to this definition">¶</a></dt>
<dd><p>Install an <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a> instance as the default global opener.
Installing an opener is only necessary if you want urlopen to use that
opener; otherwise, simply call <a class="reference internal" href="#urllib.request.OpenerDirector.open" title="urllib.request.OpenerDirector.open"><code class="xref py py-meth docutils literal"><span class="pre">OpenerDirector.open()</span></code></a> instead of
<a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a>.  The code does not check for a real
<a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a>, and any class with the appropriate interface will
work.</p>
</dd></dl>

<dl class="function">
<dt id="urllib.request.build_opener">
<code class="descclassname">urllib.request.</code><code class="descname">build_opener</code><span class="sig-paren">(</span><span class="optional">[</span><em>handler</em>, <em>...</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.build_opener" title="Permalink to this definition">¶</a></dt>
<dd><p>Return an <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a> instance, which chains the handlers in the
order given. <em>handler</em>s can be either instances of <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a>, or
subclasses of <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a> (in which case it must be possible to call
the constructor without any parameters).  Instances of the following classes
will be in front of the <em>handler</em>s, unless the <em>handler</em>s contain them,
instances of them or subclasses of them: <a class="reference internal" href="#urllib.request.ProxyHandler" title="urllib.request.ProxyHandler"><code class="xref py py-class docutils literal"><span class="pre">ProxyHandler</span></code></a> (if proxy
settings are detected), <a class="reference internal" href="#urllib.request.UnknownHandler" title="urllib.request.UnknownHandler"><code class="xref py py-class docutils literal"><span class="pre">UnknownHandler</span></code></a>, <a class="reference internal" href="#urllib.request.HTTPHandler" title="urllib.request.HTTPHandler"><code class="xref py py-class docutils literal"><span class="pre">HTTPHandler</span></code></a>,
<a class="reference internal" href="#urllib.request.HTTPDefaultErrorHandler" title="urllib.request.HTTPDefaultErrorHandler"><code class="xref py py-class docutils literal"><span class="pre">HTTPDefaultErrorHandler</span></code></a>, <a class="reference internal" href="#urllib.request.HTTPRedirectHandler" title="urllib.request.HTTPRedirectHandler"><code class="xref py py-class docutils literal"><span class="pre">HTTPRedirectHandler</span></code></a>,
<a class="reference internal" href="#urllib.request.FTPHandler" title="urllib.request.FTPHandler"><code class="xref py py-class docutils literal"><span class="pre">FTPHandler</span></code></a>, <a class="reference internal" href="#urllib.request.FileHandler" title="urllib.request.FileHandler"><code class="xref py py-class docutils literal"><span class="pre">FileHandler</span></code></a>, <a class="reference internal" href="#urllib.request.HTTPErrorProcessor" title="urllib.request.HTTPErrorProcessor"><code class="xref py py-class docutils literal"><span class="pre">HTTPErrorProcessor</span></code></a>.</p>
<p>If the Python installation has SSL support (i.e., if the <a class="reference internal" href="ssl.html#module-ssl" title="ssl: TLS/SSL wrapper for socket objects"><code class="xref py py-mod docutils literal"><span class="pre">ssl</span></code></a> module
can be imported), <a class="reference internal" href="#urllib.request.HTTPSHandler" title="urllib.request.HTTPSHandler"><code class="xref py py-class docutils literal"><span class="pre">HTTPSHandler</span></code></a> will also be added.</p>
<p>A <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a> subclass may also change its <code class="xref py py-attr docutils literal"><span class="pre">handler_order</span></code>
attribute to modify its position in the handlers list.</p>
</dd></dl>

<dl class="function">
<dt id="urllib.request.pathname2url">
<code class="descclassname">urllib.request.</code><code class="descname">pathname2url</code><span class="sig-paren">(</span><em>path</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.pathname2url" title="Permalink to this definition">¶</a></dt>
<dd><p>Convert the pathname <em>path</em> from the local syntax for a path to the form used in
the path component of a URL.  This does not produce a complete URL.  The return
value will already be quoted using the <a class="reference internal" href="urllib.parse.html#urllib.parse.quote" title="urllib.parse.quote"><code class="xref py py-func docutils literal"><span class="pre">quote()</span></code></a> function.</p>
</dd></dl>

<dl class="function">
<dt id="urllib.request.url2pathname">
<code class="descclassname">urllib.request.</code><code class="descname">url2pathname</code><span class="sig-paren">(</span><em>path</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.url2pathname" title="Permalink to this definition">¶</a></dt>
<dd><p>Convert the path component <em>path</em> from a percent-encoded URL to the local syntax for a
path.  This does not accept a complete URL.  This function uses
<a class="reference internal" href="urllib.parse.html#urllib.parse.unquote" title="urllib.parse.unquote"><code class="xref py py-func docutils literal"><span class="pre">unquote()</span></code></a> to decode <em>path</em>.</p>
</dd></dl>

<dl class="function">
<dt id="urllib.request.getproxies">
<code class="descclassname">urllib.request.</code><code class="descname">getproxies</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.getproxies" title="Permalink to this definition">¶</a></dt>
<dd><p>This helper function returns a dictionary of scheme to proxy server URL
mappings. It scans the environment for variables named <code class="docutils literal"><span class="pre">&lt;scheme&gt;_proxy</span></code>,
in a case insensitive approach, for all operating systems first, and when it
cannot find it, looks for proxy information from Mac OSX System
Configuration for Mac OS X and Windows Systems Registry for Windows.
If both lowercase and uppercase environment variables exist (and disagree),
lowercase is preferred.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">If the environment variable <code class="docutils literal"><span class="pre">REQUEST_METHOD</span></code> is set, which usually
indicates your script is running in a CGI environment, the environment
variable <code class="docutils literal"><span class="pre">HTTP_PROXY</span></code> (uppercase <code class="docutils literal"><span class="pre">_PROXY</span></code>) will be ignored. This is
because that variable can be injected by a client using the “Proxy:” HTTP
header. If you need to use an HTTP proxy in a CGI environment, either use
<code class="docutils literal"><span class="pre">ProxyHandler</span></code> explicitly, or make sure the variable name is in
lowercase (or at least the <code class="docutils literal"><span class="pre">_proxy</span></code> suffix).</p>
</div>
</dd></dl>

<p>The following classes are provided:</p>
<dl class="class">
<dt id="urllib.request.Request">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">Request</code><span class="sig-paren">(</span><em>url</em>, <em>data=None</em>, <em>headers={}</em>, <em>origin_req_host=None</em>, <em>unverifiable=False</em>, <em>method=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.Request" title="Permalink to this definition">¶</a></dt>
<dd><p>This class is an abstraction of a URL request.</p>
<p><em>url</em> should be a string containing a valid URL.</p>
<p><em>data</em> must be an object specifying additional data to send to the
server, or <code class="docutils literal"><span class="pre">None</span></code> if no such data is needed.  Currently HTTP
requests are the only ones that use <em>data</em>.  The supported object
types include bytes, file-like objects, and iterables.  If no
<code class="docutils literal"><span class="pre">Content-Length</span></code> nor <code class="docutils literal"><span class="pre">Transfer-Encoding</span></code> header field
has been provided, <a class="reference internal" href="#urllib.request.HTTPHandler" title="urllib.request.HTTPHandler"><code class="xref py py-class docutils literal"><span class="pre">HTTPHandler</span></code></a> will set these headers according
to the type of <em>data</em>.  <code class="docutils literal"><span class="pre">Content-Length</span></code> will be used to send
bytes objects, while <code class="docutils literal"><span class="pre">Transfer-Encoding:</span> <span class="pre">chunked</span></code> as specified in
<span class="target" id="index-1"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc7230.html"><strong>RFC 7230</strong></a>, Section 3.3.1 will be used to send files and other iterables.</p>
<p>For an HTTP POST request method, <em>data</em> should be a buffer in the
standard <em class="mimetype">application/x-www-form-urlencoded</em> format.  The
<a class="reference internal" href="urllib.parse.html#urllib.parse.urlencode" title="urllib.parse.urlencode"><code class="xref py py-func docutils literal"><span class="pre">urllib.parse.urlencode()</span></code></a> function takes a mapping or sequence
of 2-tuples and returns an ASCII string in this format. It should
be encoded to bytes before being used as the <em>data</em> parameter.</p>
<p><em>headers</em> should be a dictionary, and will be treated as if
<a class="reference internal" href="#urllib.request.Request.add_header" title="urllib.request.Request.add_header"><code class="xref py py-meth docutils literal"><span class="pre">add_header()</span></code></a> was called with each key and value as arguments.
This is often used to “spoof” the <code class="docutils literal"><span class="pre">User-Agent</span></code> header value, which is
used by a browser to identify itself – some HTTP servers only
allow requests coming from common browsers as opposed to scripts.
For example, Mozilla Firefox may identify itself as <code class="docutils literal"><span class="pre">&quot;Mozilla/5.0</span>
<span class="pre">(X11;</span> <span class="pre">U;</span> <span class="pre">Linux</span> <span class="pre">i686)</span> <span class="pre">Gecko/20071127</span> <span class="pre">Firefox/2.0.0.11&quot;</span></code>, while
<a class="reference internal" href="urllib.html#module-urllib" title="urllib"><code class="xref py py-mod docutils literal"><span class="pre">urllib</span></code></a>’s default user agent string is
<code class="docutils literal"><span class="pre">&quot;Python-urllib/2.6&quot;</span></code> (on Python 2.6).</p>
<p>An appropriate <code class="docutils literal"><span class="pre">Content-Type</span></code> header should be included if the <em>data</em>
argument is present.  If this header has not been provided and <em>data</em>
is not None, <code class="docutils literal"><span class="pre">Content-Type:</span> <span class="pre">application/x-www-form-urlencoded</span></code> will
be added as a default.</p>
<p>The final two arguments are only of interest for correct handling
of third-party HTTP cookies:</p>
<p><em>origin_req_host</em> should be the request-host of the origin
transaction, as defined by <span class="target" id="index-2"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc2965.html"><strong>RFC 2965</strong></a>.  It defaults to
<code class="docutils literal"><span class="pre">http.cookiejar.request_host(self)</span></code>.  This is the host name or IP
address of the original request that was initiated by the user.
For example, if the request is for an image in an HTML document,
this should be the request-host of the request for the page
containing the image.</p>
<p><em>unverifiable</em> should indicate whether the request is unverifiable,
as defined by RFC 2965.  It defaults to <code class="docutils literal"><span class="pre">False</span></code>.  An unverifiable
request is one whose URL the user did not have the option to
approve.  For example, if the request is for an image in an HTML
document, and the user had no option to approve the automatic
fetching of the image, this should be true.</p>
<p><em>method</em> should be a string that indicates the HTTP request method that
will be used (e.g. <code class="docutils literal"><span class="pre">'HEAD'</span></code>).  If provided, its value is stored in the
<a class="reference internal" href="#urllib.request.Request.method" title="urllib.request.Request.method"><code class="xref py py-attr docutils literal"><span class="pre">method</span></code></a> attribute and is used by <a class="reference internal" href="#urllib.request.Request.get_method" title="urllib.request.Request.get_method"><code class="xref py py-meth docutils literal"><span class="pre">get_method()</span></code></a>.
The default is <code class="docutils literal"><span class="pre">'GET'</span></code> if <em>data</em> is <code class="docutils literal"><span class="pre">None</span></code> or <code class="docutils literal"><span class="pre">'POST'</span></code> otherwise.
Subclasses may indicate a different default method by setting the
<a class="reference internal" href="#urllib.request.Request.method" title="urllib.request.Request.method"><code class="xref py py-attr docutils literal"><span class="pre">method</span></code></a> attribute in the class itself.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The request will not work as expected if the data object is unable
to deliver its content more than once (e.g. a file or an iterable
that can produce the content only once) and the request is retried
for HTTP redirects or authentication.  The <em>data</em> is sent to the
HTTP server right away after the headers.  There is no support for
a 100-continue expectation in the library.</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.3: </span><a class="reference internal" href="#urllib.request.Request.method" title="urllib.request.Request.method"><code class="xref py py-attr docutils literal"><span class="pre">Request.method</span></code></a> argument is added to the Request class.</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4: </span>Default <a class="reference internal" href="#urllib.request.Request.method" title="urllib.request.Request.method"><code class="xref py py-attr docutils literal"><span class="pre">Request.method</span></code></a> may be indicated at the class level.</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.6: </span>Do not raise an error if the <code class="docutils literal"><span class="pre">Content-Length</span></code> has not been
provided and <em>data</em> is neither <code class="docutils literal"><span class="pre">None</span></code> nor a bytes object.
Fall back to use chunked transfer encoding instead.</p>
</div>
</dd></dl>

<dl class="class">
<dt id="urllib.request.OpenerDirector">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">OpenerDirector</code><a class="headerlink" href="#urllib.request.OpenerDirector" title="Permalink to this definition">¶</a></dt>
<dd><p>The <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a> class opens URLs via <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a>s chained
together. It manages the chaining of handlers, and recovery from errors.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.BaseHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">BaseHandler</code><a class="headerlink" href="#urllib.request.BaseHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>This is the base class for all registered handlers — and handles only the
simple mechanics of registration.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.HTTPDefaultErrorHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">HTTPDefaultErrorHandler</code><a class="headerlink" href="#urllib.request.HTTPDefaultErrorHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>A class which defines a default handler for HTTP error responses; all responses
are turned into <a class="reference internal" href="urllib.error.html#urllib.error.HTTPError" title="urllib.error.HTTPError"><code class="xref py py-exc docutils literal"><span class="pre">HTTPError</span></code></a> exceptions.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.HTTPRedirectHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">HTTPRedirectHandler</code><a class="headerlink" href="#urllib.request.HTTPRedirectHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>A class to handle redirections.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.HTTPCookieProcessor">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">HTTPCookieProcessor</code><span class="sig-paren">(</span><em>cookiejar=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPCookieProcessor" title="Permalink to this definition">¶</a></dt>
<dd><p>A class to handle HTTP Cookies.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.ProxyHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">ProxyHandler</code><span class="sig-paren">(</span><em>proxies=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.ProxyHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>Cause requests to go through a proxy. If <em>proxies</em> is given, it must be a
dictionary mapping protocol names to URLs of proxies. The default is to read
the list of proxies from the environment variables
<span class="target" id="index-3"></span><code class="xref std std-envvar docutils literal"><span class="pre">&lt;protocol&gt;_proxy</span></code>.  If no proxy environment variables are set, then
in a Windows environment proxy settings are obtained from the registry’s
Internet Settings section, and in a Mac OS X environment proxy information
is retrieved from the OS X System Configuration Framework.</p>
<p>To disable autodetected proxy pass an empty dictionary.</p>
<p>The <span class="target" id="index-4"></span><code class="xref std std-envvar docutils literal"><span class="pre">no_proxy</span></code> environment variable can be used to specify hosts
which shouldn’t be reached via proxy; if set, it should be a comma-separated
list of hostname suffixes, optionally with <code class="docutils literal"><span class="pre">:port</span></code> appended, for example
<code class="docutils literal"><span class="pre">cern.ch,ncsa.uiuc.edu,some.host:8080</span></code>.</p>
<blockquote>
<div><div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last"><code class="docutils literal"><span class="pre">HTTP_PROXY</span></code> will be ignored if a variable <code class="docutils literal"><span class="pre">REQUEST_METHOD</span></code> is set;
see the documentation on <a class="reference internal" href="#urllib.request.getproxies" title="urllib.request.getproxies"><code class="xref py py-func docutils literal"><span class="pre">getproxies()</span></code></a>.</p>
</div>
</div></blockquote>
</dd></dl>

<dl class="class">
<dt id="urllib.request.HTTPPasswordMgr">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">HTTPPasswordMgr</code><a class="headerlink" href="#urllib.request.HTTPPasswordMgr" title="Permalink to this definition">¶</a></dt>
<dd><p>Keep a database of  <code class="docutils literal"><span class="pre">(realm,</span> <span class="pre">uri)</span> <span class="pre">-&gt;</span> <span class="pre">(user,</span> <span class="pre">password)</span></code> mappings.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.HTTPPasswordMgrWithDefaultRealm">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">HTTPPasswordMgrWithDefaultRealm</code><a class="headerlink" href="#urllib.request.HTTPPasswordMgrWithDefaultRealm" title="Permalink to this definition">¶</a></dt>
<dd><p>Keep a database of  <code class="docutils literal"><span class="pre">(realm,</span> <span class="pre">uri)</span> <span class="pre">-&gt;</span> <span class="pre">(user,</span> <span class="pre">password)</span></code> mappings. A realm of
<code class="docutils literal"><span class="pre">None</span></code> is considered a catch-all realm, which is searched if no other realm
fits.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.HTTPPasswordMgrWithPriorAuth">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">HTTPPasswordMgrWithPriorAuth</code><a class="headerlink" href="#urllib.request.HTTPPasswordMgrWithPriorAuth" title="Permalink to this definition">¶</a></dt>
<dd><p>A variant of <a class="reference internal" href="#urllib.request.HTTPPasswordMgrWithDefaultRealm" title="urllib.request.HTTPPasswordMgrWithDefaultRealm"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgrWithDefaultRealm</span></code></a> that also has a
database of <code class="docutils literal"><span class="pre">uri</span> <span class="pre">-&gt;</span> <span class="pre">is_authenticated</span></code> mappings.  Can be used by a
BasicAuth handler to determine when to send authentication credentials
immediately instead of waiting for a <code class="docutils literal"><span class="pre">401</span></code> response first.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 3.5.</span></p>
</div>
</dd></dl>

<dl class="class">
<dt id="urllib.request.AbstractBasicAuthHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">AbstractBasicAuthHandler</code><span class="sig-paren">(</span><em>password_mgr=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.AbstractBasicAuthHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>This is a mixin class that helps with HTTP authentication, both to the remote
host and to a proxy. <em>password_mgr</em>, if given, should be something that is
compatible with <a class="reference internal" href="#urllib.request.HTTPPasswordMgr" title="urllib.request.HTTPPasswordMgr"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgr</span></code></a>; refer to section
<a class="reference internal" href="#http-password-mgr"><span class="std std-ref">HTTPPasswordMgr Objects</span></a> for information on the interface that must be
supported.  If <em>passwd_mgr</em> also provides <code class="docutils literal"><span class="pre">is_authenticated</span></code> and
<code class="docutils literal"><span class="pre">update_authenticated</span></code> methods (see
<a class="reference internal" href="#http-password-mgr-with-prior-auth"><span class="std std-ref">HTTPPasswordMgrWithPriorAuth Objects</span></a>), then the handler will use the
<code class="docutils literal"><span class="pre">is_authenticated</span></code> result for a given URI to determine whether or not to
send authentication credentials with the request.  If <code class="docutils literal"><span class="pre">is_authenticated</span></code>
returns <code class="docutils literal"><span class="pre">True</span></code> for the URI, credentials are sent.  If <code class="docutils literal"><span class="pre">is_authenticated</span></code>
is <code class="docutils literal"><span class="pre">False</span></code>, credentials are not sent, and then if a <code class="docutils literal"><span class="pre">401</span></code> response is
received the request is re-sent with the authentication credentials.  If
authentication succeeds, <code class="docutils literal"><span class="pre">update_authenticated</span></code> is called to set
<code class="docutils literal"><span class="pre">is_authenticated</span></code> <code class="docutils literal"><span class="pre">True</span></code> for the URI, so that subsequent requests to
the URI or any of its super-URIs will automatically include the
authentication credentials.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 3.5: </span>Added <code class="docutils literal"><span class="pre">is_authenticated</span></code> support.</p>
</div>
</dd></dl>

<dl class="class">
<dt id="urllib.request.HTTPBasicAuthHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">HTTPBasicAuthHandler</code><span class="sig-paren">(</span><em>password_mgr=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPBasicAuthHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>Handle authentication with the remote host. <em>password_mgr</em>, if given, should
be something that is compatible with <a class="reference internal" href="#urllib.request.HTTPPasswordMgr" title="urllib.request.HTTPPasswordMgr"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgr</span></code></a>; refer to
section <a class="reference internal" href="#http-password-mgr"><span class="std std-ref">HTTPPasswordMgr Objects</span></a> for information on the interface that must
be supported. HTTPBasicAuthHandler will raise a <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal"><span class="pre">ValueError</span></code></a> when
presented with a wrong Authentication scheme.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.ProxyBasicAuthHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">ProxyBasicAuthHandler</code><span class="sig-paren">(</span><em>password_mgr=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.ProxyBasicAuthHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>Handle authentication with the proxy. <em>password_mgr</em>, if given, should be
something that is compatible with <a class="reference internal" href="#urllib.request.HTTPPasswordMgr" title="urllib.request.HTTPPasswordMgr"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgr</span></code></a>; refer to section
<a class="reference internal" href="#http-password-mgr"><span class="std std-ref">HTTPPasswordMgr Objects</span></a> for information on the interface that must be
supported.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.AbstractDigestAuthHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">AbstractDigestAuthHandler</code><span class="sig-paren">(</span><em>password_mgr=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.AbstractDigestAuthHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>This is a mixin class that helps with HTTP authentication, both to the remote
host and to a proxy. <em>password_mgr</em>, if given, should be something that is
compatible with <a class="reference internal" href="#urllib.request.HTTPPasswordMgr" title="urllib.request.HTTPPasswordMgr"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgr</span></code></a>; refer to section
<a class="reference internal" href="#http-password-mgr"><span class="std std-ref">HTTPPasswordMgr Objects</span></a> for information on the interface that must be
supported.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.HTTPDigestAuthHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">HTTPDigestAuthHandler</code><span class="sig-paren">(</span><em>password_mgr=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPDigestAuthHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>Handle authentication with the remote host. <em>password_mgr</em>, if given, should
be something that is compatible with <a class="reference internal" href="#urllib.request.HTTPPasswordMgr" title="urllib.request.HTTPPasswordMgr"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgr</span></code></a>; refer to
section <a class="reference internal" href="#http-password-mgr"><span class="std std-ref">HTTPPasswordMgr Objects</span></a> for information on the interface that must
be supported. When both Digest Authentication Handler and Basic
Authentication Handler are both added, Digest Authentication is always tried
first. If the Digest Authentication returns a 40x response again, it is sent
to Basic Authentication handler to Handle.  This Handler method will raise a
<a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal"><span class="pre">ValueError</span></code></a> when presented with an authentication scheme other than
Digest or Basic.</p>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.3: </span>Raise <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal"><span class="pre">ValueError</span></code></a> on unsupported Authentication Scheme.</p>
</div>
</dd></dl>

<dl class="class">
<dt id="urllib.request.ProxyDigestAuthHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">ProxyDigestAuthHandler</code><span class="sig-paren">(</span><em>password_mgr=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.ProxyDigestAuthHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>Handle authentication with the proxy. <em>password_mgr</em>, if given, should be
something that is compatible with <a class="reference internal" href="#urllib.request.HTTPPasswordMgr" title="urllib.request.HTTPPasswordMgr"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgr</span></code></a>; refer to section
<a class="reference internal" href="#http-password-mgr"><span class="std std-ref">HTTPPasswordMgr Objects</span></a> for information on the interface that must be
supported.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.HTTPHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">HTTPHandler</code><a class="headerlink" href="#urllib.request.HTTPHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>A class to handle opening of HTTP URLs.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.HTTPSHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">HTTPSHandler</code><span class="sig-paren">(</span><em>debuglevel=0</em>, <em>context=None</em>, <em>check_hostname=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPSHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>A class to handle opening of HTTPS URLs.  <em>context</em> and <em>check_hostname</em>
have the same meaning as in <a class="reference internal" href="http.client.html#http.client.HTTPSConnection" title="http.client.HTTPSConnection"><code class="xref py py-class docutils literal"><span class="pre">http.client.HTTPSConnection</span></code></a>.</p>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.2: </span><em>context</em> and <em>check_hostname</em> were added.</p>
</div>
</dd></dl>

<dl class="class">
<dt id="urllib.request.FileHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">FileHandler</code><a class="headerlink" href="#urllib.request.FileHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>Open local files.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.DataHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">DataHandler</code><a class="headerlink" href="#urllib.request.DataHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>Open data URLs.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="class">
<dt id="urllib.request.FTPHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">FTPHandler</code><a class="headerlink" href="#urllib.request.FTPHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>Open FTP URLs.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.CacheFTPHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">CacheFTPHandler</code><a class="headerlink" href="#urllib.request.CacheFTPHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>Open FTP URLs, keeping a cache of open FTP connections to minimize delays.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.UnknownHandler">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">UnknownHandler</code><a class="headerlink" href="#urllib.request.UnknownHandler" title="Permalink to this definition">¶</a></dt>
<dd><p>A catch-all class to handle unknown URLs.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.HTTPErrorProcessor">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">HTTPErrorProcessor</code><a class="headerlink" href="#urllib.request.HTTPErrorProcessor" title="Permalink to this definition">¶</a></dt>
<dd><p>Process HTTP error responses.</p>
</dd></dl>

<div class="section" id="request-objects">
<span id="id1"></span><h2>21.6.1. Request Objects<a class="headerlink" href="#request-objects" title="Permalink to this headline">¶</a></h2>
<p>The following methods describe <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a>’s public interface,
and so all may be overridden in subclasses.  It also defines several
public attributes that can be used by clients to inspect the parsed
request.</p>
<dl class="attribute">
<dt id="urllib.request.Request.full_url">
<code class="descclassname">Request.</code><code class="descname">full_url</code><a class="headerlink" href="#urllib.request.Request.full_url" title="Permalink to this definition">¶</a></dt>
<dd><p>The original URL passed to the constructor.</p>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4.</span></p>
</div>
<p>Request.full_url is a property with setter, getter and a deleter. Getting
<a class="reference internal" href="#urllib.request.Request.full_url" title="urllib.request.Request.full_url"><code class="xref py py-attr docutils literal"><span class="pre">full_url</span></code></a> returns the original request URL with the
fragment, if it was present.</p>
</dd></dl>

<dl class="attribute">
<dt id="urllib.request.Request.type">
<code class="descclassname">Request.</code><code class="descname">type</code><a class="headerlink" href="#urllib.request.Request.type" title="Permalink to this definition">¶</a></dt>
<dd><p>The URI scheme.</p>
</dd></dl>

<dl class="attribute">
<dt id="urllib.request.Request.host">
<code class="descclassname">Request.</code><code class="descname">host</code><a class="headerlink" href="#urllib.request.Request.host" title="Permalink to this definition">¶</a></dt>
<dd><p>The URI authority, typically a host, but may also contain a port
separated by a colon.</p>
</dd></dl>

<dl class="attribute">
<dt id="urllib.request.Request.origin_req_host">
<code class="descclassname">Request.</code><code class="descname">origin_req_host</code><a class="headerlink" href="#urllib.request.Request.origin_req_host" title="Permalink to this definition">¶</a></dt>
<dd><p>The original host for the request, without port.</p>
</dd></dl>

<dl class="attribute">
<dt id="urllib.request.Request.selector">
<code class="descclassname">Request.</code><code class="descname">selector</code><a class="headerlink" href="#urllib.request.Request.selector" title="Permalink to this definition">¶</a></dt>
<dd><p>The URI path.  If the <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> uses a proxy, then selector
will be the full URL that is passed to the proxy.</p>
</dd></dl>

<dl class="attribute">
<dt id="urllib.request.Request.data">
<code class="descclassname">Request.</code><code class="descname">data</code><a class="headerlink" href="#urllib.request.Request.data" title="Permalink to this definition">¶</a></dt>
<dd><p>The entity body for the request, or <code class="docutils literal"><span class="pre">None</span></code> if not specified.</p>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4: </span>Changing value of <a class="reference internal" href="#urllib.request.Request.data" title="urllib.request.Request.data"><code class="xref py py-attr docutils literal"><span class="pre">Request.data</span></code></a> now deletes “Content-Length”
header if it was previously set or calculated.</p>
</div>
</dd></dl>

<dl class="attribute">
<dt id="urllib.request.Request.unverifiable">
<code class="descclassname">Request.</code><code class="descname">unverifiable</code><a class="headerlink" href="#urllib.request.Request.unverifiable" title="Permalink to this definition">¶</a></dt>
<dd><p>boolean, indicates whether the request is unverifiable as defined
by RFC 2965.</p>
</dd></dl>

<dl class="attribute">
<dt id="urllib.request.Request.method">
<code class="descclassname">Request.</code><code class="descname">method</code><a class="headerlink" href="#urllib.request.Request.method" title="Permalink to this definition">¶</a></dt>
<dd><p>The HTTP request method to use.  By default its value is <a class="reference internal" href="constants.html#None" title="None"><code class="xref py py-const docutils literal"><span class="pre">None</span></code></a>,
which means that <a class="reference internal" href="#urllib.request.Request.get_method" title="urllib.request.Request.get_method"><code class="xref py py-meth docutils literal"><span class="pre">get_method()</span></code></a> will do its normal computation
of the method to be used.  Its value can be set (thus overriding the default
computation in <a class="reference internal" href="#urllib.request.Request.get_method" title="urllib.request.Request.get_method"><code class="xref py py-meth docutils literal"><span class="pre">get_method()</span></code></a>) either by providing a default
value by setting it at the class level in a <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> subclass, or by
passing a value in to the <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> constructor via the <em>method</em>
argument.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 3.3.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4: </span>A default value can now be set in subclasses; previously it could only
be set via the constructor argument.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="urllib.request.Request.get_method">
<code class="descclassname">Request.</code><code class="descname">get_method</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.Request.get_method" title="Permalink to this definition">¶</a></dt>
<dd><p>Return a string indicating the HTTP request method.  If
<a class="reference internal" href="#urllib.request.Request.method" title="urllib.request.Request.method"><code class="xref py py-attr docutils literal"><span class="pre">Request.method</span></code></a> is not <code class="docutils literal"><span class="pre">None</span></code>, return its value, otherwise return
<code class="docutils literal"><span class="pre">'GET'</span></code> if <a class="reference internal" href="#urllib.request.Request.data" title="urllib.request.Request.data"><code class="xref py py-attr docutils literal"><span class="pre">Request.data</span></code></a> is <code class="docutils literal"><span class="pre">None</span></code>, or <code class="docutils literal"><span class="pre">'POST'</span></code> if it’s not.
This is only meaningful for HTTP requests.</p>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.3: </span>get_method now looks at the value of <a class="reference internal" href="#urllib.request.Request.method" title="urllib.request.Request.method"><code class="xref py py-attr docutils literal"><span class="pre">Request.method</span></code></a>.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="urllib.request.Request.add_header">
<code class="descclassname">Request.</code><code class="descname">add_header</code><span class="sig-paren">(</span><em>key</em>, <em>val</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.Request.add_header" title="Permalink to this definition">¶</a></dt>
<dd><p>Add another header to the request.  Headers are currently ignored by all
handlers except HTTP handlers, where they are added to the list of headers sent
to the server.  Note that there cannot be more than one header with the same
name, and later calls will overwrite previous calls in case the <em>key</em> collides.
Currently, this is no loss of HTTP functionality, since all headers which have
meaning when used more than once have a (header-specific) way of gaining the
same functionality using only one header.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.Request.add_unredirected_header">
<code class="descclassname">Request.</code><code class="descname">add_unredirected_header</code><span class="sig-paren">(</span><em>key</em>, <em>header</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.Request.add_unredirected_header" title="Permalink to this definition">¶</a></dt>
<dd><p>Add a header that will not be added to a redirected request.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.Request.has_header">
<code class="descclassname">Request.</code><code class="descname">has_header</code><span class="sig-paren">(</span><em>header</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.Request.has_header" title="Permalink to this definition">¶</a></dt>
<dd><p>Return whether the instance has the named header (checks both regular and
unredirected).</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.Request.remove_header">
<code class="descclassname">Request.</code><code class="descname">remove_header</code><span class="sig-paren">(</span><em>header</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.Request.remove_header" title="Permalink to this definition">¶</a></dt>
<dd><p>Remove named header from the request instance (both from regular and
unredirected headers).</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="method">
<dt id="urllib.request.Request.get_full_url">
<code class="descclassname">Request.</code><code class="descname">get_full_url</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.Request.get_full_url" title="Permalink to this definition">¶</a></dt>
<dd><p>Return the URL given in the constructor.</p>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4.</span></p>
</div>
<p>Returns <a class="reference internal" href="#urllib.request.Request.full_url" title="urllib.request.Request.full_url"><code class="xref py py-attr docutils literal"><span class="pre">Request.full_url</span></code></a></p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.Request.set_proxy">
<code class="descclassname">Request.</code><code class="descname">set_proxy</code><span class="sig-paren">(</span><em>host</em>, <em>type</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.Request.set_proxy" title="Permalink to this definition">¶</a></dt>
<dd><p>Prepare the request by connecting to a proxy server. The <em>host</em> and <em>type</em> will
replace those of the instance, and the instance’s selector will be the original
URL given in the constructor.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.Request.get_header">
<code class="descclassname">Request.</code><code class="descname">get_header</code><span class="sig-paren">(</span><em>header_name</em>, <em>default=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.Request.get_header" title="Permalink to this definition">¶</a></dt>
<dd><p>Return the value of the given header. If the header is not present, return
the default value.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.Request.header_items">
<code class="descclassname">Request.</code><code class="descname">header_items</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.Request.header_items" title="Permalink to this definition">¶</a></dt>
<dd><p>Return a list of tuples (header_name, header_value) of the Request headers.</p>
</dd></dl>

<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4: </span>The request methods add_data, has_data, get_data, get_type, get_host,
get_selector, get_origin_req_host and is_unverifiable that were deprecated
since 3.3 have been removed.</p>
</div>
</div>
<div class="section" id="openerdirector-objects">
<span id="opener-director-objects"></span><h2>21.6.2. OpenerDirector Objects<a class="headerlink" href="#openerdirector-objects" title="Permalink to this headline">¶</a></h2>
<p><a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a> instances have the following methods:</p>
<dl class="method">
<dt id="urllib.request.OpenerDirector.add_handler">
<code class="descclassname">OpenerDirector.</code><code class="descname">add_handler</code><span class="sig-paren">(</span><em>handler</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.OpenerDirector.add_handler" title="Permalink to this definition">¶</a></dt>
<dd><p><em>handler</em> should be an instance of <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a>.  The following methods
are searched, and added to the possible chains (note that HTTP errors are a
special case).</p>
<ul class="simple">
<li><code class="xref py py-meth docutils literal"><span class="pre">protocol_open()</span></code> — signal that the handler knows how to open <em>protocol</em>
URLs.</li>
<li><code class="xref py py-meth docutils literal"><span class="pre">http_error_type()</span></code> — signal that the handler knows how to handle HTTP
errors with HTTP error code <em>type</em>.</li>
<li><code class="xref py py-meth docutils literal"><span class="pre">protocol_error()</span></code> — signal that the handler knows how to handle errors
from (non-<code class="docutils literal"><span class="pre">http</span></code>) <em>protocol</em>.</li>
<li><code class="xref py py-meth docutils literal"><span class="pre">protocol_request()</span></code> — signal that the handler knows how to pre-process
<em>protocol</em> requests.</li>
<li><code class="xref py py-meth docutils literal"><span class="pre">protocol_response()</span></code> — signal that the handler knows how to
post-process <em>protocol</em> responses.</li>
</ul>
</dd></dl>

<dl class="method">
<dt id="urllib.request.OpenerDirector.open">
<code class="descclassname">OpenerDirector.</code><code class="descname">open</code><span class="sig-paren">(</span><em>url</em>, <em>data=None</em><span class="optional">[</span>, <em>timeout</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.OpenerDirector.open" title="Permalink to this definition">¶</a></dt>
<dd><p>Open the given <em>url</em> (which can be a request object or a string), optionally
passing the given <em>data</em>. Arguments, return values and exceptions raised are
the same as those of <a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a> (which simply calls the <a class="reference internal" href="functions.html#open" title="open"><code class="xref py py-meth docutils literal"><span class="pre">open()</span></code></a>
method on the currently installed global <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a>).  The
optional <em>timeout</em> parameter specifies a timeout in seconds for blocking
operations like the connection attempt (if not specified, the global default
timeout setting will be used). The timeout feature actually works only for
HTTP, HTTPS and FTP connections).</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.OpenerDirector.error">
<code class="descclassname">OpenerDirector.</code><code class="descname">error</code><span class="sig-paren">(</span><em>proto</em>, <em>*args</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.OpenerDirector.error" title="Permalink to this definition">¶</a></dt>
<dd><p>Handle an error of the given protocol.  This will call the registered error
handlers for the given protocol with the given arguments (which are protocol
specific).  The HTTP protocol is a special case which uses the HTTP response
code to determine the specific error handler; refer to the <code class="xref py py-meth docutils literal"><span class="pre">http_error_*()</span></code>
methods of the handler classes.</p>
<p>Return values and exceptions raised are the same as those of <a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a>.</p>
</dd></dl>

<p>OpenerDirector objects open URLs in three stages:</p>
<p>The order in which these methods are called within each stage is determined by
sorting the handler instances.</p>
<ol class="arabic">
<li><p class="first">Every handler with a method named like <code class="xref py py-meth docutils literal"><span class="pre">protocol_request()</span></code> has that
method called to pre-process the request.</p>
</li>
<li><p class="first">Handlers with a method named like <code class="xref py py-meth docutils literal"><span class="pre">protocol_open()</span></code> are called to handle
the request. This stage ends when a handler either returns a non-<a class="reference internal" href="constants.html#None" title="None"><code class="xref py py-const docutils literal"><span class="pre">None</span></code></a>
value (ie. a response), or raises an exception (usually
<a class="reference internal" href="urllib.error.html#urllib.error.URLError" title="urllib.error.URLError"><code class="xref py py-exc docutils literal"><span class="pre">URLError</span></code></a>).  Exceptions are allowed to propagate.</p>
<p>In fact, the above algorithm is first tried for methods named
<code class="xref py py-meth docutils literal"><span class="pre">default_open()</span></code>.  If all such methods return <a class="reference internal" href="constants.html#None" title="None"><code class="xref py py-const docutils literal"><span class="pre">None</span></code></a>, the algorithm
is repeated for methods named like <code class="xref py py-meth docutils literal"><span class="pre">protocol_open()</span></code>.  If all such methods
return <a class="reference internal" href="constants.html#None" title="None"><code class="xref py py-const docutils literal"><span class="pre">None</span></code></a>, the algorithm is repeated for methods named
<code class="xref py py-meth docutils literal"><span class="pre">unknown_open()</span></code>.</p>
<p>Note that the implementation of these methods may involve calls of the parent
<a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a> instance’s <a class="reference internal" href="#urllib.request.OpenerDirector.open" title="urllib.request.OpenerDirector.open"><code class="xref py py-meth docutils literal"><span class="pre">open()</span></code></a> and
<a class="reference internal" href="#urllib.request.OpenerDirector.error" title="urllib.request.OpenerDirector.error"><code class="xref py py-meth docutils literal"><span class="pre">error()</span></code></a> methods.</p>
</li>
<li><p class="first">Every handler with a method named like <code class="xref py py-meth docutils literal"><span class="pre">protocol_response()</span></code> has that
method called to post-process the response.</p>
</li>
</ol>
</div>
<div class="section" id="basehandler-objects">
<span id="base-handler-objects"></span><h2>21.6.3. BaseHandler Objects<a class="headerlink" href="#basehandler-objects" title="Permalink to this headline">¶</a></h2>
<p><a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a> objects provide a couple of methods that are directly
useful, and others that are meant to be used by derived classes.  These are
intended for direct use:</p>
<dl class="method">
<dt id="urllib.request.BaseHandler.add_parent">
<code class="descclassname">BaseHandler.</code><code class="descname">add_parent</code><span class="sig-paren">(</span><em>director</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.BaseHandler.add_parent" title="Permalink to this definition">¶</a></dt>
<dd><p>Add a director as parent.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.BaseHandler.close">
<code class="descclassname">BaseHandler.</code><code class="descname">close</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.BaseHandler.close" title="Permalink to this definition">¶</a></dt>
<dd><p>Remove any parents.</p>
</dd></dl>

<p>The following attribute and methods should only be used by classes derived from
<a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a>.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The convention has been adopted that subclasses defining
<code class="xref py py-meth docutils literal"><span class="pre">protocol_request()</span></code> or <code class="xref py py-meth docutils literal"><span class="pre">protocol_response()</span></code> methods are named
<code class="xref py py-class docutils literal"><span class="pre">*Processor</span></code>; all others are named <code class="xref py py-class docutils literal"><span class="pre">*Handler</span></code>.</p>
</div>
<dl class="attribute">
<dt id="urllib.request.BaseHandler.parent">
<code class="descclassname">BaseHandler.</code><code class="descname">parent</code><a class="headerlink" href="#urllib.request.BaseHandler.parent" title="Permalink to this definition">¶</a></dt>
<dd><p>A valid <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a>, which can be used to open using a different
protocol, or handle errors.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.BaseHandler.default_open">
<code class="descclassname">BaseHandler.</code><code class="descname">default_open</code><span class="sig-paren">(</span><em>req</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.BaseHandler.default_open" title="Permalink to this definition">¶</a></dt>
<dd><p>This method is <em>not</em> defined in <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a>, but subclasses should
define it if they want to catch all URLs.</p>
<p>This method, if implemented, will be called by the parent
<a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a>.  It should return a file-like object as described in
the return value of the <a class="reference internal" href="functions.html#open" title="open"><code class="xref py py-meth docutils literal"><span class="pre">open()</span></code></a> of <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a>, or <code class="docutils literal"><span class="pre">None</span></code>.
It should raise <a class="reference internal" href="urllib.error.html#urllib.error.URLError" title="urllib.error.URLError"><code class="xref py py-exc docutils literal"><span class="pre">URLError</span></code></a>, unless a truly exceptional
thing happens (for example, <a class="reference internal" href="exceptions.html#MemoryError" title="MemoryError"><code class="xref py py-exc docutils literal"><span class="pre">MemoryError</span></code></a> should not be mapped to
<code class="xref py py-exc docutils literal"><span class="pre">URLError</span></code>).</p>
<p>This method will be called before any protocol-specific open method.</p>
</dd></dl>

<dl class="method">
<dt>
<code class="descclassname">BaseHandler.</code><code class="descname">protocol_open</code><span class="sig-paren">(</span><em>req</em><span class="sig-paren">)</span></dt>
<dd><p>This method is <em>not</em> defined in <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a>, but subclasses should
define it if they want to handle URLs with the given protocol.</p>
<p>This method, if defined, will be called by the parent <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a>.
Return values should be the same as for  <a class="reference internal" href="#urllib.request.BaseHandler.default_open" title="urllib.request.BaseHandler.default_open"><code class="xref py py-meth docutils literal"><span class="pre">default_open()</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.BaseHandler.unknown_open">
<code class="descclassname">BaseHandler.</code><code class="descname">unknown_open</code><span class="sig-paren">(</span><em>req</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.BaseHandler.unknown_open" title="Permalink to this definition">¶</a></dt>
<dd><p>This method is <em>not</em> defined in <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a>, but subclasses should
define it if they want to catch all URLs with no specific registered handler to
open it.</p>
<p>This method, if implemented, will be called by the <a class="reference internal" href="#urllib.request.BaseHandler.parent" title="urllib.request.BaseHandler.parent"><code class="xref py py-attr docutils literal"><span class="pre">parent</span></code></a>
<a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a>.  Return values should be the same as for
<a class="reference internal" href="#urllib.request.BaseHandler.default_open" title="urllib.request.BaseHandler.default_open"><code class="xref py py-meth docutils literal"><span class="pre">default_open()</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.BaseHandler.http_error_default">
<code class="descclassname">BaseHandler.</code><code class="descname">http_error_default</code><span class="sig-paren">(</span><em>req</em>, <em>fp</em>, <em>code</em>, <em>msg</em>, <em>hdrs</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.BaseHandler.http_error_default" title="Permalink to this definition">¶</a></dt>
<dd><p>This method is <em>not</em> defined in <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a>, but subclasses should
override it if they intend to provide a catch-all for otherwise unhandled HTTP
errors.  It will be called automatically by the  <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a> getting
the error, and should not normally be called in other circumstances.</p>
<p><em>req</em> will be a <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> object, <em>fp</em> will be a file-like object with
the HTTP error body, <em>code</em> will be the three-digit code of the error, <em>msg</em>
will be the user-visible explanation of the code and <em>hdrs</em> will be a mapping
object with the headers of the error.</p>
<p>Return values and exceptions raised should be the same as those of
<a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.BaseHandler.http_error_nnn">
<code class="descclassname">BaseHandler.</code><code class="descname">http_error_nnn</code><span class="sig-paren">(</span><em>req</em>, <em>fp</em>, <em>code</em>, <em>msg</em>, <em>hdrs</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.BaseHandler.http_error_nnn" title="Permalink to this definition">¶</a></dt>
<dd><p><em>nnn</em> should be a three-digit HTTP error code.  This method is also not defined
in <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a>, but will be called, if it exists, on an instance of a
subclass, when an HTTP error with code <em>nnn</em> occurs.</p>
<p>Subclasses should override this method to handle specific HTTP errors.</p>
<p>Arguments, return values and exceptions raised should be the same as for
<a class="reference internal" href="#urllib.request.BaseHandler.http_error_default" title="urllib.request.BaseHandler.http_error_default"><code class="xref py py-meth docutils literal"><span class="pre">http_error_default()</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt>
<code class="descclassname">BaseHandler.</code><code class="descname">protocol_request</code><span class="sig-paren">(</span><em>req</em><span class="sig-paren">)</span></dt>
<dd><p>This method is <em>not</em> defined in <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a>, but subclasses should
define it if they want to pre-process requests of the given protocol.</p>
<p>This method, if defined, will be called by the parent <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a>.
<em>req</em> will be a <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> object. The return value should be a
<a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> object.</p>
</dd></dl>

<dl class="method">
<dt>
<code class="descclassname">BaseHandler.</code><code class="descname">protocol_response</code><span class="sig-paren">(</span><em>req</em>, <em>response</em><span class="sig-paren">)</span></dt>
<dd><p>This method is <em>not</em> defined in <a class="reference internal" href="#urllib.request.BaseHandler" title="urllib.request.BaseHandler"><code class="xref py py-class docutils literal"><span class="pre">BaseHandler</span></code></a>, but subclasses should
define it if they want to post-process responses of the given protocol.</p>
<p>This method, if defined, will be called by the parent <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a>.
<em>req</em> will be a <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> object. <em>response</em> will be an object
implementing the same interface as the return value of <a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a>.  The
return value should implement the same interface as the return value of
<a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a>.</p>
</dd></dl>

</div>
<div class="section" id="httpredirecthandler-objects">
<span id="http-redirect-handler"></span><h2>21.6.4. HTTPRedirectHandler Objects<a class="headerlink" href="#httpredirecthandler-objects" title="Permalink to this headline">¶</a></h2>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>Some HTTP redirections require action from this module’s client code.  If this
is the case, <a class="reference internal" href="urllib.error.html#urllib.error.HTTPError" title="urllib.error.HTTPError"><code class="xref py py-exc docutils literal"><span class="pre">HTTPError</span></code></a> is raised.  See <span class="target" id="index-5"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc2616.html"><strong>RFC 2616</strong></a> for
details of the precise meanings of the various redirection codes.</p>
<p class="last">An <code class="xref py py-class docutils literal"><span class="pre">HTTPError</span></code> exception raised as a security consideration if the
HTTPRedirectHandler is presented with a redirected URL which is not an HTTP,
HTTPS or FTP URL.</p>
</div>
<dl class="method">
<dt id="urllib.request.HTTPRedirectHandler.redirect_request">
<code class="descclassname">HTTPRedirectHandler.</code><code class="descname">redirect_request</code><span class="sig-paren">(</span><em>req</em>, <em>fp</em>, <em>code</em>, <em>msg</em>, <em>hdrs</em>, <em>newurl</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPRedirectHandler.redirect_request" title="Permalink to this definition">¶</a></dt>
<dd><p>Return a <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> or <code class="docutils literal"><span class="pre">None</span></code> in response to a redirect. This is called
by the default implementations of the <code class="xref py py-meth docutils literal"><span class="pre">http_error_30*()</span></code> methods when a
redirection is received from the server.  If a redirection should take place,
return a new <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> to allow <code class="xref py py-meth docutils literal"><span class="pre">http_error_30*()</span></code> to perform the
redirect to <em>newurl</em>.  Otherwise, raise <a class="reference internal" href="urllib.error.html#urllib.error.HTTPError" title="urllib.error.HTTPError"><code class="xref py py-exc docutils literal"><span class="pre">HTTPError</span></code></a> if
no other handler should try to handle this URL, or return <code class="docutils literal"><span class="pre">None</span></code> if you
can’t but another handler might.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The default implementation of this method does not strictly follow <span class="target" id="index-6"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc2616.html"><strong>RFC 2616</strong></a>,
which says that 301 and 302 responses to <code class="docutils literal"><span class="pre">POST</span></code> requests must not be
automatically redirected without confirmation by the user.  In reality, browsers
do allow automatic redirection of these responses, changing the POST to a
<code class="docutils literal"><span class="pre">GET</span></code>, and the default implementation reproduces this behavior.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="urllib.request.HTTPRedirectHandler.http_error_301">
<code class="descclassname">HTTPRedirectHandler.</code><code class="descname">http_error_301</code><span class="sig-paren">(</span><em>req</em>, <em>fp</em>, <em>code</em>, <em>msg</em>, <em>hdrs</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPRedirectHandler.http_error_301" title="Permalink to this definition">¶</a></dt>
<dd><p>Redirect to the <code class="docutils literal"><span class="pre">Location:</span></code> or <code class="docutils literal"><span class="pre">URI:</span></code> URL.  This method is called by the
parent <a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a> when getting an HTTP ‘moved permanently’ response.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.HTTPRedirectHandler.http_error_302">
<code class="descclassname">HTTPRedirectHandler.</code><code class="descname">http_error_302</code><span class="sig-paren">(</span><em>req</em>, <em>fp</em>, <em>code</em>, <em>msg</em>, <em>hdrs</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPRedirectHandler.http_error_302" title="Permalink to this definition">¶</a></dt>
<dd><p>The same as <a class="reference internal" href="#urllib.request.HTTPRedirectHandler.http_error_301" title="urllib.request.HTTPRedirectHandler.http_error_301"><code class="xref py py-meth docutils literal"><span class="pre">http_error_301()</span></code></a>, but called for the ‘found’ response.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.HTTPRedirectHandler.http_error_303">
<code class="descclassname">HTTPRedirectHandler.</code><code class="descname">http_error_303</code><span class="sig-paren">(</span><em>req</em>, <em>fp</em>, <em>code</em>, <em>msg</em>, <em>hdrs</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPRedirectHandler.http_error_303" title="Permalink to this definition">¶</a></dt>
<dd><p>The same as <a class="reference internal" href="#urllib.request.HTTPRedirectHandler.http_error_301" title="urllib.request.HTTPRedirectHandler.http_error_301"><code class="xref py py-meth docutils literal"><span class="pre">http_error_301()</span></code></a>, but called for the ‘see other’ response.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.HTTPRedirectHandler.http_error_307">
<code class="descclassname">HTTPRedirectHandler.</code><code class="descname">http_error_307</code><span class="sig-paren">(</span><em>req</em>, <em>fp</em>, <em>code</em>, <em>msg</em>, <em>hdrs</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPRedirectHandler.http_error_307" title="Permalink to this definition">¶</a></dt>
<dd><p>The same as <a class="reference internal" href="#urllib.request.HTTPRedirectHandler.http_error_301" title="urllib.request.HTTPRedirectHandler.http_error_301"><code class="xref py py-meth docutils literal"><span class="pre">http_error_301()</span></code></a>, but called for the ‘temporary redirect’
response.</p>
</dd></dl>

</div>
<div class="section" id="httpcookieprocessor-objects">
<span id="http-cookie-processor"></span><h2>21.6.5. HTTPCookieProcessor Objects<a class="headerlink" href="#httpcookieprocessor-objects" title="Permalink to this headline">¶</a></h2>
<p><a class="reference internal" href="#urllib.request.HTTPCookieProcessor" title="urllib.request.HTTPCookieProcessor"><code class="xref py py-class docutils literal"><span class="pre">HTTPCookieProcessor</span></code></a> instances have one attribute:</p>
<dl class="attribute">
<dt id="urllib.request.HTTPCookieProcessor.cookiejar">
<code class="descclassname">HTTPCookieProcessor.</code><code class="descname">cookiejar</code><a class="headerlink" href="#urllib.request.HTTPCookieProcessor.cookiejar" title="Permalink to this definition">¶</a></dt>
<dd><p>The <a class="reference internal" href="http.cookiejar.html#http.cookiejar.CookieJar" title="http.cookiejar.CookieJar"><code class="xref py py-class docutils literal"><span class="pre">http.cookiejar.CookieJar</span></code></a> in which cookies are stored.</p>
</dd></dl>

</div>
<div class="section" id="proxyhandler-objects">
<span id="proxy-handler"></span><h2>21.6.6. ProxyHandler Objects<a class="headerlink" href="#proxyhandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt>
<code class="descclassname">ProxyHandler.</code><code class="descname">protocol_open</code><span class="sig-paren">(</span><em>request</em><span class="sig-paren">)</span></dt>
<dd><p>The <a class="reference internal" href="#urllib.request.ProxyHandler" title="urllib.request.ProxyHandler"><code class="xref py py-class docutils literal"><span class="pre">ProxyHandler</span></code></a> will have a method <code class="xref py py-meth docutils literal"><span class="pre">protocol_open()</span></code> for every
<em>protocol</em> which has a proxy in the <em>proxies</em> dictionary given in the
constructor.  The method will modify requests to go through the proxy, by
calling <code class="docutils literal"><span class="pre">request.set_proxy()</span></code>, and call the next handler in the chain to
actually execute the protocol.</p>
</dd></dl>

</div>
<div class="section" id="httppasswordmgr-objects">
<span id="http-password-mgr"></span><h2>21.6.7. HTTPPasswordMgr Objects<a class="headerlink" href="#httppasswordmgr-objects" title="Permalink to this headline">¶</a></h2>
<p>These methods are available on <a class="reference internal" href="#urllib.request.HTTPPasswordMgr" title="urllib.request.HTTPPasswordMgr"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgr</span></code></a> and
<a class="reference internal" href="#urllib.request.HTTPPasswordMgrWithDefaultRealm" title="urllib.request.HTTPPasswordMgrWithDefaultRealm"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgrWithDefaultRealm</span></code></a> objects.</p>
<dl class="method">
<dt id="urllib.request.HTTPPasswordMgr.add_password">
<code class="descclassname">HTTPPasswordMgr.</code><code class="descname">add_password</code><span class="sig-paren">(</span><em>realm</em>, <em>uri</em>, <em>user</em>, <em>passwd</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPPasswordMgr.add_password" title="Permalink to this definition">¶</a></dt>
<dd><p><em>uri</em> can be either a single URI, or a sequence of URIs. <em>realm</em>, <em>user</em> and
<em>passwd</em> must be strings. This causes <code class="docutils literal"><span class="pre">(user,</span> <span class="pre">passwd)</span></code> to be used as
authentication tokens when authentication for <em>realm</em> and a super-URI of any of
the given URIs is given.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.HTTPPasswordMgr.find_user_password">
<code class="descclassname">HTTPPasswordMgr.</code><code class="descname">find_user_password</code><span class="sig-paren">(</span><em>realm</em>, <em>authuri</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPPasswordMgr.find_user_password" title="Permalink to this definition">¶</a></dt>
<dd><p>Get user/password for given realm and URI, if any.  This method will return
<code class="docutils literal"><span class="pre">(None,</span> <span class="pre">None)</span></code> if there is no matching user/password.</p>
<p>For <a class="reference internal" href="#urllib.request.HTTPPasswordMgrWithDefaultRealm" title="urllib.request.HTTPPasswordMgrWithDefaultRealm"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgrWithDefaultRealm</span></code></a> objects, the realm <code class="docutils literal"><span class="pre">None</span></code> will be
searched if the given <em>realm</em> has no matching user/password.</p>
</dd></dl>

</div>
<div class="section" id="httppasswordmgrwithpriorauth-objects">
<span id="http-password-mgr-with-prior-auth"></span><h2>21.6.8. HTTPPasswordMgrWithPriorAuth Objects<a class="headerlink" href="#httppasswordmgrwithpriorauth-objects" title="Permalink to this headline">¶</a></h2>
<p>This password manager extends <a class="reference internal" href="#urllib.request.HTTPPasswordMgrWithDefaultRealm" title="urllib.request.HTTPPasswordMgrWithDefaultRealm"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgrWithDefaultRealm</span></code></a> to support
tracking URIs for which authentication credentials should always be sent.</p>
<dl class="method">
<dt id="urllib.request.HTTPPasswordMgrWithPriorAuth.add_password">
<code class="descclassname">HTTPPasswordMgrWithPriorAuth.</code><code class="descname">add_password</code><span class="sig-paren">(</span><em>realm</em>, <em>uri</em>, <em>user</em>, <em>passwd</em>, <em>is_authenticated=False</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPPasswordMgrWithPriorAuth.add_password" title="Permalink to this definition">¶</a></dt>
<dd><p><em>realm</em>, <em>uri</em>, <em>user</em>, <em>passwd</em> are as for
<a class="reference internal" href="#urllib.request.HTTPPasswordMgr.add_password" title="urllib.request.HTTPPasswordMgr.add_password"><code class="xref py py-meth docutils literal"><span class="pre">HTTPPasswordMgr.add_password()</span></code></a>.  <em>is_authenticated</em> sets the initial
value of the <code class="docutils literal"><span class="pre">is_authenticated</span></code> flag for the given URI or list of URIs.
If <em>is_authenticated</em> is specified as <code class="docutils literal"><span class="pre">True</span></code>, <em>realm</em> is ignored.</p>
</dd></dl>

<dl class="method">
<dt>
<code class="descclassname">HTTPPasswordMgr.</code><code class="descname">find_user_password</code><span class="sig-paren">(</span><em>realm</em>, <em>authuri</em><span class="sig-paren">)</span></dt>
<dd><p>Same as for <a class="reference internal" href="#urllib.request.HTTPPasswordMgrWithDefaultRealm" title="urllib.request.HTTPPasswordMgrWithDefaultRealm"><code class="xref py py-class docutils literal"><span class="pre">HTTPPasswordMgrWithDefaultRealm</span></code></a> objects</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.HTTPPasswordMgrWithPriorAuth.update_authenticated">
<code class="descclassname">HTTPPasswordMgrWithPriorAuth.</code><code class="descname">update_authenticated</code><span class="sig-paren">(</span><em>self</em>, <em>uri</em>, <em>is_authenticated=False</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPPasswordMgrWithPriorAuth.update_authenticated" title="Permalink to this definition">¶</a></dt>
<dd><p>Update the <code class="docutils literal"><span class="pre">is_authenticated</span></code> flag for the given <em>uri</em> or list
of URIs.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.HTTPPasswordMgrWithPriorAuth.is_authenticated">
<code class="descclassname">HTTPPasswordMgrWithPriorAuth.</code><code class="descname">is_authenticated</code><span class="sig-paren">(</span><em>self</em>, <em>authuri</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPPasswordMgrWithPriorAuth.is_authenticated" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the current state of the <code class="docutils literal"><span class="pre">is_authenticated</span></code> flag for
the given URI.</p>
</dd></dl>

</div>
<div class="section" id="abstractbasicauthhandler-objects">
<span id="abstract-basic-auth-handler"></span><h2>21.6.9. AbstractBasicAuthHandler Objects<a class="headerlink" href="#abstractbasicauthhandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.AbstractBasicAuthHandler.http_error_auth_reqed">
<code class="descclassname">AbstractBasicAuthHandler.</code><code class="descname">http_error_auth_reqed</code><span class="sig-paren">(</span><em>authreq</em>, <em>host</em>, <em>req</em>, <em>headers</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.AbstractBasicAuthHandler.http_error_auth_reqed" title="Permalink to this definition">¶</a></dt>
<dd><p>Handle an authentication request by getting a user/password pair, and re-trying
the request.  <em>authreq</em> should be the name of the header where the information
about the realm is included in the request, <em>host</em> specifies the URL and path to
authenticate for, <em>req</em> should be the (failed) <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> object, and
<em>headers</em> should be the error headers.</p>
<p><em>host</em> is either an authority (e.g. <code class="docutils literal"><span class="pre">&quot;python.org&quot;</span></code>) or a URL containing an
authority component (e.g. <code class="docutils literal"><span class="pre">&quot;http://python.org/&quot;</span></code>). In either case, the
authority must not contain a userinfo component (so, <code class="docutils literal"><span class="pre">&quot;python.org&quot;</span></code> and
<code class="docutils literal"><span class="pre">&quot;python.org:80&quot;</span></code> are fine, <code class="docutils literal"><span class="pre">&quot;joe:password&#64;python.org&quot;</span></code> is not).</p>
</dd></dl>

</div>
<div class="section" id="httpbasicauthhandler-objects">
<span id="http-basic-auth-handler"></span><h2>21.6.10. HTTPBasicAuthHandler Objects<a class="headerlink" href="#httpbasicauthhandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.HTTPBasicAuthHandler.http_error_401">
<code class="descclassname">HTTPBasicAuthHandler.</code><code class="descname">http_error_401</code><span class="sig-paren">(</span><em>req</em>, <em>fp</em>, <em>code</em>, <em>msg</em>, <em>hdrs</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPBasicAuthHandler.http_error_401" title="Permalink to this definition">¶</a></dt>
<dd><p>Retry the request with authentication information, if available.</p>
</dd></dl>

</div>
<div class="section" id="proxybasicauthhandler-objects">
<span id="proxy-basic-auth-handler"></span><h2>21.6.11. ProxyBasicAuthHandler Objects<a class="headerlink" href="#proxybasicauthhandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.ProxyBasicAuthHandler.http_error_407">
<code class="descclassname">ProxyBasicAuthHandler.</code><code class="descname">http_error_407</code><span class="sig-paren">(</span><em>req</em>, <em>fp</em>, <em>code</em>, <em>msg</em>, <em>hdrs</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.ProxyBasicAuthHandler.http_error_407" title="Permalink to this definition">¶</a></dt>
<dd><p>Retry the request with authentication information, if available.</p>
</dd></dl>

</div>
<div class="section" id="abstractdigestauthhandler-objects">
<span id="abstract-digest-auth-handler"></span><h2>21.6.12. AbstractDigestAuthHandler Objects<a class="headerlink" href="#abstractdigestauthhandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.AbstractDigestAuthHandler.http_error_auth_reqed">
<code class="descclassname">AbstractDigestAuthHandler.</code><code class="descname">http_error_auth_reqed</code><span class="sig-paren">(</span><em>authreq</em>, <em>host</em>, <em>req</em>, <em>headers</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.AbstractDigestAuthHandler.http_error_auth_reqed" title="Permalink to this definition">¶</a></dt>
<dd><p><em>authreq</em> should be the name of the header where the information about the realm
is included in the request, <em>host</em> should be the host to authenticate to, <em>req</em>
should be the (failed) <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> object, and <em>headers</em> should be the
error headers.</p>
</dd></dl>

</div>
<div class="section" id="httpdigestauthhandler-objects">
<span id="http-digest-auth-handler"></span><h2>21.6.13. HTTPDigestAuthHandler Objects<a class="headerlink" href="#httpdigestauthhandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.HTTPDigestAuthHandler.http_error_401">
<code class="descclassname">HTTPDigestAuthHandler.</code><code class="descname">http_error_401</code><span class="sig-paren">(</span><em>req</em>, <em>fp</em>, <em>code</em>, <em>msg</em>, <em>hdrs</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPDigestAuthHandler.http_error_401" title="Permalink to this definition">¶</a></dt>
<dd><p>Retry the request with authentication information, if available.</p>
</dd></dl>

</div>
<div class="section" id="proxydigestauthhandler-objects">
<span id="proxy-digest-auth-handler"></span><h2>21.6.14. ProxyDigestAuthHandler Objects<a class="headerlink" href="#proxydigestauthhandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.ProxyDigestAuthHandler.http_error_407">
<code class="descclassname">ProxyDigestAuthHandler.</code><code class="descname">http_error_407</code><span class="sig-paren">(</span><em>req</em>, <em>fp</em>, <em>code</em>, <em>msg</em>, <em>hdrs</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.ProxyDigestAuthHandler.http_error_407" title="Permalink to this definition">¶</a></dt>
<dd><p>Retry the request with authentication information, if available.</p>
</dd></dl>

</div>
<div class="section" id="httphandler-objects">
<span id="http-handler-objects"></span><h2>21.6.15. HTTPHandler Objects<a class="headerlink" href="#httphandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.HTTPHandler.http_open">
<code class="descclassname">HTTPHandler.</code><code class="descname">http_open</code><span class="sig-paren">(</span><em>req</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPHandler.http_open" title="Permalink to this definition">¶</a></dt>
<dd><p>Send an HTTP request, which can be either GET or POST, depending on
<code class="docutils literal"><span class="pre">req.has_data()</span></code>.</p>
</dd></dl>

</div>
<div class="section" id="httpshandler-objects">
<span id="https-handler-objects"></span><h2>21.6.16. HTTPSHandler Objects<a class="headerlink" href="#httpshandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.HTTPSHandler.https_open">
<code class="descclassname">HTTPSHandler.</code><code class="descname">https_open</code><span class="sig-paren">(</span><em>req</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPSHandler.https_open" title="Permalink to this definition">¶</a></dt>
<dd><p>Send an HTTPS request, which can be either GET or POST, depending on
<code class="docutils literal"><span class="pre">req.has_data()</span></code>.</p>
</dd></dl>

</div>
<div class="section" id="filehandler-objects">
<span id="file-handler-objects"></span><h2>21.6.17. FileHandler Objects<a class="headerlink" href="#filehandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.FileHandler.file_open">
<code class="descclassname">FileHandler.</code><code class="descname">file_open</code><span class="sig-paren">(</span><em>req</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.FileHandler.file_open" title="Permalink to this definition">¶</a></dt>
<dd><p>Open the file locally, if there is no host name, or the host name is
<code class="docutils literal"><span class="pre">'localhost'</span></code>.</p>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.2: </span>This method is applicable only for local hostnames.  When a remote
hostname is given, an <a class="reference internal" href="urllib.error.html#urllib.error.URLError" title="urllib.error.URLError"><code class="xref py py-exc docutils literal"><span class="pre">URLError</span></code></a> is raised.</p>
</div>
</dd></dl>

</div>
<div class="section" id="datahandler-objects">
<span id="data-handler-objects"></span><h2>21.6.18. DataHandler Objects<a class="headerlink" href="#datahandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.DataHandler.data_open">
<code class="descclassname">DataHandler.</code><code class="descname">data_open</code><span class="sig-paren">(</span><em>req</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.DataHandler.data_open" title="Permalink to this definition">¶</a></dt>
<dd><p>Read a data URL. This kind of URL contains the content encoded in the URL
itself. The data URL syntax is specified in <span class="target" id="index-7"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc2397.html"><strong>RFC 2397</strong></a>. This implementation
ignores white spaces in base64 encoded data URLs so the URL may be wrapped
in whatever source file it comes from. But even though some browsers don’t
mind about a missing padding at the end of a base64 encoded data URL, this
implementation will raise an <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal"><span class="pre">ValueError</span></code></a> in that case.</p>
</dd></dl>

</div>
<div class="section" id="ftphandler-objects">
<span id="ftp-handler-objects"></span><h2>21.6.19. FTPHandler Objects<a class="headerlink" href="#ftphandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.FTPHandler.ftp_open">
<code class="descclassname">FTPHandler.</code><code class="descname">ftp_open</code><span class="sig-paren">(</span><em>req</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.FTPHandler.ftp_open" title="Permalink to this definition">¶</a></dt>
<dd><p>Open the FTP file indicated by <em>req</em>. The login is always done with empty
username and password.</p>
</dd></dl>

</div>
<div class="section" id="cacheftphandler-objects">
<span id="cacheftp-handler-objects"></span><h2>21.6.20. CacheFTPHandler Objects<a class="headerlink" href="#cacheftphandler-objects" title="Permalink to this headline">¶</a></h2>
<p><a class="reference internal" href="#urllib.request.CacheFTPHandler" title="urllib.request.CacheFTPHandler"><code class="xref py py-class docutils literal"><span class="pre">CacheFTPHandler</span></code></a> objects are <a class="reference internal" href="#urllib.request.FTPHandler" title="urllib.request.FTPHandler"><code class="xref py py-class docutils literal"><span class="pre">FTPHandler</span></code></a> objects with the
following additional methods:</p>
<dl class="method">
<dt id="urllib.request.CacheFTPHandler.setTimeout">
<code class="descclassname">CacheFTPHandler.</code><code class="descname">setTimeout</code><span class="sig-paren">(</span><em>t</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.CacheFTPHandler.setTimeout" title="Permalink to this definition">¶</a></dt>
<dd><p>Set timeout of connections to <em>t</em> seconds.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.CacheFTPHandler.setMaxConns">
<code class="descclassname">CacheFTPHandler.</code><code class="descname">setMaxConns</code><span class="sig-paren">(</span><em>m</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.CacheFTPHandler.setMaxConns" title="Permalink to this definition">¶</a></dt>
<dd><p>Set maximum number of cached connections to <em>m</em>.</p>
</dd></dl>

</div>
<div class="section" id="unknownhandler-objects">
<span id="unknown-handler-objects"></span><h2>21.6.21. UnknownHandler Objects<a class="headerlink" href="#unknownhandler-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.UnknownHandler.unknown_open">
<code class="descclassname">UnknownHandler.</code><code class="descname">unknown_open</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.UnknownHandler.unknown_open" title="Permalink to this definition">¶</a></dt>
<dd><p>Raise a <a class="reference internal" href="urllib.error.html#urllib.error.URLError" title="urllib.error.URLError"><code class="xref py py-exc docutils literal"><span class="pre">URLError</span></code></a> exception.</p>
</dd></dl>

</div>
<div class="section" id="httperrorprocessor-objects">
<span id="http-error-processor-objects"></span><h2>21.6.22. HTTPErrorProcessor Objects<a class="headerlink" href="#httperrorprocessor-objects" title="Permalink to this headline">¶</a></h2>
<dl class="method">
<dt id="urllib.request.HTTPErrorProcessor.http_response">
<code class="descclassname">HTTPErrorProcessor.</code><code class="descname">http_response</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPErrorProcessor.http_response" title="Permalink to this definition">¶</a></dt>
<dd><p>Process HTTP error responses.</p>
<p>For 200 error codes, the response object is returned immediately.</p>
<p>For non-200 error codes, this simply passes the job on to the
<code class="xref py py-meth docutils literal"><span class="pre">protocol_error_code()</span></code> handler methods, via <a class="reference internal" href="#urllib.request.OpenerDirector.error" title="urllib.request.OpenerDirector.error"><code class="xref py py-meth docutils literal"><span class="pre">OpenerDirector.error()</span></code></a>.
Eventually, <a class="reference internal" href="#urllib.request.HTTPDefaultErrorHandler" title="urllib.request.HTTPDefaultErrorHandler"><code class="xref py py-class docutils literal"><span class="pre">HTTPDefaultErrorHandler</span></code></a> will raise an
<a class="reference internal" href="urllib.error.html#urllib.error.HTTPError" title="urllib.error.HTTPError"><code class="xref py py-exc docutils literal"><span class="pre">HTTPError</span></code></a> if no other handler handles the error.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.HTTPErrorProcessor.https_response">
<code class="descclassname">HTTPErrorProcessor.</code><code class="descname">https_response</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.HTTPErrorProcessor.https_response" title="Permalink to this definition">¶</a></dt>
<dd><p>Process HTTPS error responses.</p>
<p>The behavior is same as <a class="reference internal" href="#urllib.request.HTTPErrorProcessor.http_response" title="urllib.request.HTTPErrorProcessor.http_response"><code class="xref py py-meth docutils literal"><span class="pre">http_response()</span></code></a>.</p>
</dd></dl>

</div>
<div class="section" id="examples">
<span id="urllib-request-examples"></span><h2>21.6.23. Examples<a class="headerlink" href="#examples" title="Permalink to this headline">¶</a></h2>
<p>In addition to the examples below, more examples are given in
<a class="reference internal" href="../howto/urllib2.html#urllib-howto"><span class="std std-ref">HOWTO Fetch Internet Resources Using The urllib Package</span></a>.</p>
<p>This example gets the python.org main page and displays the first 300 bytes of
it.</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">with</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">urlopen</span><span class="p">(</span><span class="s1">&#39;http://www.python.org/&#39;</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="mi">300</span><span class="p">))</span>
<span class="gp">...</span>
<span class="go">b&#39;&lt;!DOCTYPE html PUBLIC &quot;-//W3C//DTD XHTML 1.0 Transitional//EN&quot;</span>
<span class="go">&quot;http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd&quot;&gt;\n\n\n&lt;html</span>
<span class="go">xmlns=&quot;http://www.w3.org/1999/xhtml&quot; xml:lang=&quot;en&quot; lang=&quot;en&quot;&gt;\n\n&lt;head&gt;\n</span>
<span class="go">&lt;meta http-equiv=&quot;content-type&quot; content=&quot;text/html; charset=utf-8&quot; /&gt;\n</span>
<span class="go">&lt;title&gt;Python Programming &#39;</span>
</pre></div>
</div>
<p>Note that urlopen returns a bytes object.  This is because there is no way
for urlopen to automatically determine the encoding of the byte stream
it receives from the HTTP server. In general, a program will decode
the returned bytes object to string once it determines or guesses
the appropriate encoding.</p>
<p>The following W3C document, <a class="reference external" href="https://www.w3.org/International/O-charset">https://www.w3.org/International/O-charset</a>, lists
the various ways in which an (X)HTML or an XML document could have specified its
encoding information.</p>
<p>As the python.org website uses <em>utf-8</em> encoding as specified in its meta tag, we
will use the same for decoding the bytes object.</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">with</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">urlopen</span><span class="p">(</span><span class="s1">&#39;http://www.python.org/&#39;</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="mi">100</span><span class="p">)</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">&#39;utf-8&#39;</span><span class="p">))</span>
<span class="gp">...</span>
<span class="go">&lt;!DOCTYPE html PUBLIC &quot;-//W3C//DTD XHTML 1.0 Transitional//EN&quot;</span>
<span class="go">&quot;http://www.w3.org/TR/xhtml1/DTD/xhtm</span>
</pre></div>
</div>
<p>It is also possible to achieve the same result without using the
<a class="reference internal" href="../glossary.html#term-context-manager"><span class="xref std std-term">context manager</span></a> approach.</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">f</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">urlopen</span><span class="p">(</span><span class="s1">&#39;http://www.python.org/&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="mi">100</span><span class="p">)</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">&#39;utf-8&#39;</span><span class="p">))</span>
<span class="go">&lt;!DOCTYPE html PUBLIC &quot;-//W3C//DTD XHTML 1.0 Transitional//EN&quot;</span>
<span class="go">&quot;http://www.w3.org/TR/xhtml1/DTD/xhtm</span>
</pre></div>
</div>
<p>In the following example, we are sending a data-stream to the stdin of a CGI
and reading the data it returns to us. Note that this example will only work
when the Python installation supports SSL.</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">req</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">Request</span><span class="p">(</span><span class="n">url</span><span class="o">=</span><span class="s1">&#39;https://localhost/cgi-bin/test.cgi&#39;</span><span class="p">,</span>
<span class="gp">... </span>                      <span class="n">data</span><span class="o">=</span><span class="sa">b</span><span class="s1">&#39;This data is passed to stdin of the CGI&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">with</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">urlopen</span><span class="p">(</span><span class="n">req</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">()</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">&#39;utf-8&#39;</span><span class="p">))</span>
<span class="gp">...</span>
<span class="go">Got Data: &quot;This data is passed to stdin of the CGI&quot;</span>
</pre></div>
</div>
<p>The code for the sample CGI used in the above example is:</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="ch">#!/usr/bin/env python</span>
<span class="kn">import</span> <span class="nn">sys</span>
<span class="n">data</span> <span class="o">=</span> <span class="n">sys</span><span class="o">.</span><span class="n">stdin</span><span class="o">.</span><span class="n">read</span><span class="p">()</span>
<span class="nb">print</span><span class="p">(</span><span class="s1">&#39;Content-type: text/plain</span><span class="se">\n\n</span><span class="s1">Got Data: &quot;</span><span class="si">%s</span><span class="s1">&quot;&#39;</span> <span class="o">%</span> <span class="n">data</span><span class="p">)</span>
</pre></div>
</div>
<p>Here is an example of doing a <code class="docutils literal"><span class="pre">PUT</span></code> request using <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a>:</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="n">DATA</span> <span class="o">=</span> <span class="sa">b</span><span class="s1">&#39;some data&#39;</span>
<span class="n">req</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">Request</span><span class="p">(</span><span class="n">url</span><span class="o">=</span><span class="s1">&#39;http://localhost:8080&#39;</span><span class="p">,</span> <span class="n">data</span><span class="o">=</span><span class="n">DATA</span><span class="p">,</span><span class="n">method</span><span class="o">=</span><span class="s1">&#39;PUT&#39;</span><span class="p">)</span>
<span class="k">with</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">urlopen</span><span class="p">(</span><span class="n">req</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
    <span class="k">pass</span>
<span class="nb">print</span><span class="p">(</span><span class="n">f</span><span class="o">.</span><span class="n">status</span><span class="p">)</span>
<span class="nb">print</span><span class="p">(</span><span class="n">f</span><span class="o">.</span><span class="n">reason</span><span class="p">)</span>
</pre></div>
</div>
<p>Use of Basic HTTP Authentication:</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="c1"># Create an OpenerDirector with support for Basic HTTP Authentication...</span>
<span class="n">auth_handler</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">HTTPBasicAuthHandler</span><span class="p">()</span>
<span class="n">auth_handler</span><span class="o">.</span><span class="n">add_password</span><span class="p">(</span><span class="n">realm</span><span class="o">=</span><span class="s1">&#39;PDQ Application&#39;</span><span class="p">,</span>
                          <span class="n">uri</span><span class="o">=</span><span class="s1">&#39;https://mahler:8092/site-updates.py&#39;</span><span class="p">,</span>
                          <span class="n">user</span><span class="o">=</span><span class="s1">&#39;klem&#39;</span><span class="p">,</span>
                          <span class="n">passwd</span><span class="o">=</span><span class="s1">&#39;kadidd!ehopper&#39;</span><span class="p">)</span>
<span class="n">opener</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">build_opener</span><span class="p">(</span><span class="n">auth_handler</span><span class="p">)</span>
<span class="c1"># ...and install it globally so it can be used with urlopen.</span>
<span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">install_opener</span><span class="p">(</span><span class="n">opener</span><span class="p">)</span>
<span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">urlopen</span><span class="p">(</span><span class="s1">&#39;http://www.example.com/login.html&#39;</span><span class="p">)</span>
</pre></div>
</div>
<p><a class="reference internal" href="#urllib.request.build_opener" title="urllib.request.build_opener"><code class="xref py py-func docutils literal"><span class="pre">build_opener()</span></code></a> provides many handlers by default, including a
<a class="reference internal" href="#urllib.request.ProxyHandler" title="urllib.request.ProxyHandler"><code class="xref py py-class docutils literal"><span class="pre">ProxyHandler</span></code></a>.  By default, <a class="reference internal" href="#urllib.request.ProxyHandler" title="urllib.request.ProxyHandler"><code class="xref py py-class docutils literal"><span class="pre">ProxyHandler</span></code></a> uses the environment
variables named <code class="docutils literal"><span class="pre">&lt;scheme&gt;_proxy</span></code>, where <code class="docutils literal"><span class="pre">&lt;scheme&gt;</span></code> is the URL scheme
involved.  For example, the <span class="target" id="index-8"></span><code class="xref std std-envvar docutils literal"><span class="pre">http_proxy</span></code> environment variable is read to
obtain the HTTP proxy’s URL.</p>
<p>This example replaces the default <a class="reference internal" href="#urllib.request.ProxyHandler" title="urllib.request.ProxyHandler"><code class="xref py py-class docutils literal"><span class="pre">ProxyHandler</span></code></a> with one that uses
programmatically-supplied proxy URLs, and adds proxy authorization support with
<a class="reference internal" href="#urllib.request.ProxyBasicAuthHandler" title="urllib.request.ProxyBasicAuthHandler"><code class="xref py py-class docutils literal"><span class="pre">ProxyBasicAuthHandler</span></code></a>.</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="n">proxy_handler</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">ProxyHandler</span><span class="p">({</span><span class="s1">&#39;http&#39;</span><span class="p">:</span> <span class="s1">&#39;http://www.example.com:3128/&#39;</span><span class="p">})</span>
<span class="n">proxy_auth_handler</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">ProxyBasicAuthHandler</span><span class="p">()</span>
<span class="n">proxy_auth_handler</span><span class="o">.</span><span class="n">add_password</span><span class="p">(</span><span class="s1">&#39;realm&#39;</span><span class="p">,</span> <span class="s1">&#39;host&#39;</span><span class="p">,</span> <span class="s1">&#39;username&#39;</span><span class="p">,</span> <span class="s1">&#39;password&#39;</span><span class="p">)</span>

<span class="n">opener</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">build_opener</span><span class="p">(</span><span class="n">proxy_handler</span><span class="p">,</span> <span class="n">proxy_auth_handler</span><span class="p">)</span>
<span class="c1"># This time, rather than install the OpenerDirector, we use it directly:</span>
<span class="n">opener</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s1">&#39;http://www.example.com/login.html&#39;</span><span class="p">)</span>
</pre></div>
</div>
<p>Adding HTTP headers:</p>
<p>Use the <em>headers</em> argument to the <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> constructor, or:</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="n">req</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">Request</span><span class="p">(</span><span class="s1">&#39;http://www.example.com/&#39;</span><span class="p">)</span>
<span class="n">req</span><span class="o">.</span><span class="n">add_header</span><span class="p">(</span><span class="s1">&#39;Referer&#39;</span><span class="p">,</span> <span class="s1">&#39;http://www.python.org/&#39;</span><span class="p">)</span>
<span class="c1"># Customize the default User-Agent header value:</span>
<span class="n">req</span><span class="o">.</span><span class="n">add_header</span><span class="p">(</span><span class="s1">&#39;User-Agent&#39;</span><span class="p">,</span> <span class="s1">&#39;urllib-example/0.1 (Contact: . . .)&#39;</span><span class="p">)</span>
<span class="n">r</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">urlopen</span><span class="p">(</span><span class="n">req</span><span class="p">)</span>
</pre></div>
</div>
<p><a class="reference internal" href="#urllib.request.OpenerDirector" title="urllib.request.OpenerDirector"><code class="xref py py-class docutils literal"><span class="pre">OpenerDirector</span></code></a> automatically adds a <em class="mailheader">User-Agent</em> header to
every <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a>.  To change this:</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="n">opener</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">build_opener</span><span class="p">()</span>
<span class="n">opener</span><span class="o">.</span><span class="n">addheaders</span> <span class="o">=</span> <span class="p">[(</span><span class="s1">&#39;User-agent&#39;</span><span class="p">,</span> <span class="s1">&#39;Mozilla/5.0&#39;</span><span class="p">)]</span>
<span class="n">opener</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s1">&#39;http://www.example.com/&#39;</span><span class="p">)</span>
</pre></div>
</div>
<p>Also, remember that a few standard headers (<em class="mailheader">Content-Length</em>,
<em class="mailheader">Content-Type</em> and <em class="mailheader">Host</em>)
are added when the <a class="reference internal" href="#urllib.request.Request" title="urllib.request.Request"><code class="xref py py-class docutils literal"><span class="pre">Request</span></code></a> is passed to <a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a> (or
<a class="reference internal" href="#urllib.request.OpenerDirector.open" title="urllib.request.OpenerDirector.open"><code class="xref py py-meth docutils literal"><span class="pre">OpenerDirector.open()</span></code></a>).</p>
<p id="urllib-examples">Here is an example session that uses the <code class="docutils literal"><span class="pre">GET</span></code> method to retrieve a URL
containing parameters:</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">urllib.parse</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">params</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">parse</span><span class="o">.</span><span class="n">urlencode</span><span class="p">({</span><span class="s1">&#39;spam&#39;</span><span class="p">:</span> <span class="mi">1</span><span class="p">,</span> <span class="s1">&#39;eggs&#39;</span><span class="p">:</span> <span class="mi">2</span><span class="p">,</span> <span class="s1">&#39;bacon&#39;</span><span class="p">:</span> <span class="mi">0</span><span class="p">})</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">url</span> <span class="o">=</span> <span class="s2">&quot;http://www.musi-cal.com/cgi-bin/query?</span><span class="si">%s</span><span class="s2">&quot;</span> <span class="o">%</span> <span class="n">params</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">with</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">urlopen</span><span class="p">(</span><span class="n">url</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">()</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">&#39;utf-8&#39;</span><span class="p">))</span>
<span class="gp">...</span>
</pre></div>
</div>
<p>The following example uses the <code class="docutils literal"><span class="pre">POST</span></code> method instead. Note that params output
from urlencode is encoded to bytes before it is sent to urlopen as data:</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">urllib.parse</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">data</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">parse</span><span class="o">.</span><span class="n">urlencode</span><span class="p">({</span><span class="s1">&#39;spam&#39;</span><span class="p">:</span> <span class="mi">1</span><span class="p">,</span> <span class="s1">&#39;eggs&#39;</span><span class="p">:</span> <span class="mi">2</span><span class="p">,</span> <span class="s1">&#39;bacon&#39;</span><span class="p">:</span> <span class="mi">0</span><span class="p">})</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">data</span> <span class="o">=</span> <span class="n">data</span><span class="o">.</span><span class="n">encode</span><span class="p">(</span><span class="s1">&#39;ascii&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">with</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">urlopen</span><span class="p">(</span><span class="s2">&quot;http://requestb.in/xrbl82xr&quot;</span><span class="p">,</span> <span class="n">data</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">()</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">&#39;utf-8&#39;</span><span class="p">))</span>
<span class="gp">...</span>
</pre></div>
</div>
<p>The following example uses an explicitly specified HTTP proxy, overriding
environment settings:</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">proxies</span> <span class="o">=</span> <span class="p">{</span><span class="s1">&#39;http&#39;</span><span class="p">:</span> <span class="s1">&#39;http://proxy.example.com:8080/&#39;</span><span class="p">}</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">opener</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">FancyURLopener</span><span class="p">(</span><span class="n">proxies</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">with</span> <span class="n">opener</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s2">&quot;http://www.python.org&quot;</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="gp">... </span>    <span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">()</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">&#39;utf-8&#39;</span><span class="p">)</span>
<span class="gp">...</span>
</pre></div>
</div>
<p>The following example uses no proxies at all, overriding environment settings:</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">opener</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">FancyURLopener</span><span class="p">({})</span>
<span class="gp">&gt;&gt;&gt; </span><span class="k">with</span> <span class="n">opener</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s2">&quot;http://www.python.org/&quot;</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="gp">... </span>    <span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">()</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">&#39;utf-8&#39;</span><span class="p">)</span>
<span class="gp">...</span>
</pre></div>
</div>
</div>
<div class="section" id="legacy-interface">
<h2>21.6.24. Legacy interface<a class="headerlink" href="#legacy-interface" title="Permalink to this headline">¶</a></h2>
<p>The following functions and classes are ported from the Python 2 module
<code class="docutils literal"><span class="pre">urllib</span></code> (as opposed to <code class="docutils literal"><span class="pre">urllib2</span></code>).  They might become deprecated at
some point in the future.</p>
<dl class="function">
<dt id="urllib.request.urlretrieve">
<code class="descclassname">urllib.request.</code><code class="descname">urlretrieve</code><span class="sig-paren">(</span><em>url</em>, <em>filename=None</em>, <em>reporthook=None</em>, <em>data=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.urlretrieve" title="Permalink to this definition">¶</a></dt>
<dd><p>Copy a network object denoted by a URL to a local file. If the URL
points to a local file, the object will not be copied unless filename is supplied.
Return a tuple <code class="docutils literal"><span class="pre">(filename,</span> <span class="pre">headers)</span></code> where <em>filename</em> is the
local file name under which the object can be found, and <em>headers</em> is whatever
the <code class="xref py py-meth docutils literal"><span class="pre">info()</span></code> method of the object returned by <a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a> returned (for
a remote object). Exceptions are the same as for <a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a>.</p>
<p>The second argument, if present, specifies the file location to copy to (if
absent, the location will be a tempfile with a generated name). The third
argument, if present, is a hook function that will be called once on
establishment of the network connection and once after each block read
thereafter.  The hook will be passed three arguments; a count of blocks
transferred so far, a block size in bytes, and the total size of the file.  The
third argument may be <code class="docutils literal"><span class="pre">-1</span></code> on older FTP servers which do not return a file
size in response to a retrieval request.</p>
<p>The following example illustrates the most common usage scenario:</p>
<div class="highlight-python3"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">urllib.request</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">local_filename</span><span class="p">,</span> <span class="n">headers</span> <span class="o">=</span> <span class="n">urllib</span><span class="o">.</span><span class="n">request</span><span class="o">.</span><span class="n">urlretrieve</span><span class="p">(</span><span class="s1">&#39;http://python.org/&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">html</span> <span class="o">=</span> <span class="nb">open</span><span class="p">(</span><span class="n">local_filename</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">html</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
</pre></div>
</div>
<p>If the <em>url</em> uses the <code class="file docutils literal"><span class="pre">http:</span></code> scheme identifier, the optional <em>data</em>
argument may be given to specify a <code class="docutils literal"><span class="pre">POST</span></code> request (normally the request
type is <code class="docutils literal"><span class="pre">GET</span></code>).  The <em>data</em> argument must be a bytes object in standard
<em class="mimetype">application/x-www-form-urlencoded</em> format; see the
<a class="reference internal" href="urllib.parse.html#urllib.parse.urlencode" title="urllib.parse.urlencode"><code class="xref py py-func docutils literal"><span class="pre">urllib.parse.urlencode()</span></code></a> function.</p>
<p><a class="reference internal" href="#urllib.request.urlretrieve" title="urllib.request.urlretrieve"><code class="xref py py-func docutils literal"><span class="pre">urlretrieve()</span></code></a> will raise <code class="xref py py-exc docutils literal"><span class="pre">ContentTooShortError</span></code> when it detects that
the amount of data available  was less than the expected amount (which is the
size reported by a  <em>Content-Length</em> header). This can occur, for example, when
the  download is interrupted.</p>
<p>The <em>Content-Length</em> is treated as a lower bound: if there’s more data  to read,
urlretrieve reads more data, but if less data is available,  it raises the
exception.</p>
<p>You can still retrieve the downloaded data in this case, it is stored  in the
<code class="xref py py-attr docutils literal"><span class="pre">content</span></code> attribute of the exception instance.</p>
<p>If no <em>Content-Length</em> header was supplied, urlretrieve can not check the size
of the data it has downloaded, and just returns it.  In this case you just have
to assume that the download was successful.</p>
</dd></dl>

<dl class="function">
<dt id="urllib.request.urlcleanup">
<code class="descclassname">urllib.request.</code><code class="descname">urlcleanup</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.urlcleanup" title="Permalink to this definition">¶</a></dt>
<dd><p>Cleans up temporary files that may have been left behind by previous
calls to <a class="reference internal" href="#urllib.request.urlretrieve" title="urllib.request.urlretrieve"><code class="xref py py-func docutils literal"><span class="pre">urlretrieve()</span></code></a>.</p>
</dd></dl>

<dl class="class">
<dt id="urllib.request.URLopener">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">URLopener</code><span class="sig-paren">(</span><em>proxies=None</em>, <em>**x509</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.URLopener" title="Permalink to this definition">¶</a></dt>
<dd><div class="deprecated">
<p><span class="versionmodified">Deprecated since version 3.3.</span></p>
</div>
<p>Base class for opening and reading URLs.  Unless you need to support opening
objects using schemes other than <code class="file docutils literal"><span class="pre">http:</span></code>, <code class="file docutils literal"><span class="pre">ftp:</span></code>, or <code class="file docutils literal"><span class="pre">file:</span></code>,
you probably want to use <a class="reference internal" href="#urllib.request.FancyURLopener" title="urllib.request.FancyURLopener"><code class="xref py py-class docutils literal"><span class="pre">FancyURLopener</span></code></a>.</p>
<p>By default, the <a class="reference internal" href="#urllib.request.URLopener" title="urllib.request.URLopener"><code class="xref py py-class docutils literal"><span class="pre">URLopener</span></code></a> class sends a <em class="mailheader">User-Agent</em> header
of <code class="docutils literal"><span class="pre">urllib/VVV</span></code>, where <em>VVV</em> is the <a class="reference internal" href="urllib.html#module-urllib" title="urllib"><code class="xref py py-mod docutils literal"><span class="pre">urllib</span></code></a> version number.
Applications can define their own <em class="mailheader">User-Agent</em> header by subclassing
<a class="reference internal" href="#urllib.request.URLopener" title="urllib.request.URLopener"><code class="xref py py-class docutils literal"><span class="pre">URLopener</span></code></a> or <a class="reference internal" href="#urllib.request.FancyURLopener" title="urllib.request.FancyURLopener"><code class="xref py py-class docutils literal"><span class="pre">FancyURLopener</span></code></a> and setting the class attribute
<a class="reference internal" href="#urllib.request.URLopener.version" title="urllib.request.URLopener.version"><code class="xref py py-attr docutils literal"><span class="pre">version</span></code></a> to an appropriate string value in the subclass definition.</p>
<p>The optional <em>proxies</em> parameter should be a dictionary mapping scheme names to
proxy URLs, where an empty dictionary turns proxies off completely.  Its default
value is <code class="docutils literal"><span class="pre">None</span></code>, in which case environmental proxy settings will be used if
present, as discussed in the definition of <a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a>, above.</p>
<p>Additional keyword parameters, collected in <em>x509</em>, may be used for
authentication of the client when using the <code class="file docutils literal"><span class="pre">https:</span></code> scheme.  The keywords
<em>key_file</em> and <em>cert_file</em> are supported to provide an  SSL key and certificate;
both are needed to support client authentication.</p>
<p><a class="reference internal" href="#urllib.request.URLopener" title="urllib.request.URLopener"><code class="xref py py-class docutils literal"><span class="pre">URLopener</span></code></a> objects will raise an <a class="reference internal" href="exceptions.html#OSError" title="OSError"><code class="xref py py-exc docutils literal"><span class="pre">OSError</span></code></a> exception if the server
returns an error code.</p>
<dl class="method">
<dt id="urllib.request.URLopener.open">
<code class="descname">open</code><span class="sig-paren">(</span><em>fullurl</em>, <em>data=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.URLopener.open" title="Permalink to this definition">¶</a></dt>
<dd><p>Open <em>fullurl</em> using the appropriate protocol.  This method sets up cache and
proxy information, then calls the appropriate open method with its input
arguments.  If the scheme is not recognized, <a class="reference internal" href="#urllib.request.URLopener.open_unknown" title="urllib.request.URLopener.open_unknown"><code class="xref py py-meth docutils literal"><span class="pre">open_unknown()</span></code></a> is called.
The <em>data</em> argument has the same meaning as the <em>data</em> argument of
<a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.URLopener.open_unknown">
<code class="descname">open_unknown</code><span class="sig-paren">(</span><em>fullurl</em>, <em>data=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.URLopener.open_unknown" title="Permalink to this definition">¶</a></dt>
<dd><p>Overridable interface to open unknown URL types.</p>
</dd></dl>

<dl class="method">
<dt id="urllib.request.URLopener.retrieve">
<code class="descname">retrieve</code><span class="sig-paren">(</span><em>url</em>, <em>filename=None</em>, <em>reporthook=None</em>, <em>data=None</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.URLopener.retrieve" title="Permalink to this definition">¶</a></dt>
<dd><p>Retrieves the contents of <em>url</em> and places it in <em>filename</em>.  The return value
is a tuple consisting of a local filename and either an
<a class="reference internal" href="email.compat32-message.html#email.message.Message" title="email.message.Message"><code class="xref py py-class docutils literal"><span class="pre">email.message.Message</span></code></a> object containing the response headers (for remote
URLs) or <code class="docutils literal"><span class="pre">None</span></code> (for local URLs).  The caller must then open and read the
contents of <em>filename</em>.  If <em>filename</em> is not given and the URL refers to a
local file, the input filename is returned.  If the URL is non-local and
<em>filename</em> is not given, the filename is the output of <a class="reference internal" href="tempfile.html#tempfile.mktemp" title="tempfile.mktemp"><code class="xref py py-func docutils literal"><span class="pre">tempfile.mktemp()</span></code></a>
with a suffix that matches the suffix of the last path component of the input
URL.  If <em>reporthook</em> is given, it must be a function accepting three numeric
parameters: A chunk number, the maximum size chunks are read in and the total size of the download
(-1 if unknown).  It will be called once at the start and after each chunk of data is read from the
network.  <em>reporthook</em> is ignored for local URLs.</p>
<p>If the <em>url</em> uses the <code class="file docutils literal"><span class="pre">http:</span></code> scheme identifier, the optional <em>data</em>
argument may be given to specify a <code class="docutils literal"><span class="pre">POST</span></code> request (normally the request type
is <code class="docutils literal"><span class="pre">GET</span></code>).  The <em>data</em> argument must in standard
<em class="mimetype">application/x-www-form-urlencoded</em> format; see the
<a class="reference internal" href="urllib.parse.html#urllib.parse.urlencode" title="urllib.parse.urlencode"><code class="xref py py-func docutils literal"><span class="pre">urllib.parse.urlencode()</span></code></a> function.</p>
</dd></dl>

<dl class="attribute">
<dt id="urllib.request.URLopener.version">
<code class="descname">version</code><a class="headerlink" href="#urllib.request.URLopener.version" title="Permalink to this definition">¶</a></dt>
<dd><p>Variable that specifies the user agent of the opener object.  To get
<a class="reference internal" href="urllib.html#module-urllib" title="urllib"><code class="xref py py-mod docutils literal"><span class="pre">urllib</span></code></a> to tell servers that it is a particular user agent, set this in a
subclass as a class variable or in the constructor before calling the base
constructor.</p>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="urllib.request.FancyURLopener">
<em class="property">class </em><code class="descclassname">urllib.request.</code><code class="descname">FancyURLopener</code><span class="sig-paren">(</span><em>...</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.FancyURLopener" title="Permalink to this definition">¶</a></dt>
<dd><div class="deprecated">
<p><span class="versionmodified">Deprecated since version 3.3.</span></p>
</div>
<p><a class="reference internal" href="#urllib.request.FancyURLopener" title="urllib.request.FancyURLopener"><code class="xref py py-class docutils literal"><span class="pre">FancyURLopener</span></code></a> subclasses <a class="reference internal" href="#urllib.request.URLopener" title="urllib.request.URLopener"><code class="xref py py-class docutils literal"><span class="pre">URLopener</span></code></a> providing default handling
for the following HTTP response codes: 301, 302, 303, 307 and 401.  For the 30x
response codes listed above, the <em class="mailheader">Location</em> header is used to fetch
the actual URL.  For 401 response codes (authentication required), basic HTTP
authentication is performed.  For the 30x response codes, recursion is bounded
by the value of the <em>maxtries</em> attribute, which defaults to 10.</p>
<p>For all other response codes, the method <code class="xref py py-meth docutils literal"><span class="pre">http_error_default()</span></code> is called
which you can override in subclasses to handle the error appropriately.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">According to the letter of <span class="target" id="index-9"></span><a class="rfc reference external" href="https://tools.ietf.org/html/rfc2616.html"><strong>RFC 2616</strong></a>, 301 and 302 responses to POST requests
must not be automatically redirected without confirmation by the user.  In
reality, browsers do allow automatic redirection of these responses, changing
the POST to a GET, and <a class="reference internal" href="urllib.html#module-urllib" title="urllib"><code class="xref py py-mod docutils literal"><span class="pre">urllib</span></code></a> reproduces this behaviour.</p>
</div>
<p>The parameters to the constructor are the same as those for <a class="reference internal" href="#urllib.request.URLopener" title="urllib.request.URLopener"><code class="xref py py-class docutils literal"><span class="pre">URLopener</span></code></a>.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">When performing basic authentication, a <a class="reference internal" href="#urllib.request.FancyURLopener" title="urllib.request.FancyURLopener"><code class="xref py py-class docutils literal"><span class="pre">FancyURLopener</span></code></a> instance calls
its <a class="reference internal" href="#urllib.request.FancyURLopener.prompt_user_passwd" title="urllib.request.FancyURLopener.prompt_user_passwd"><code class="xref py py-meth docutils literal"><span class="pre">prompt_user_passwd()</span></code></a> method.  The default implementation asks the
users for the required information on the controlling terminal.  A subclass may
override this method to support more appropriate behavior if needed.</p>
</div>
<p>The <a class="reference internal" href="#urllib.request.FancyURLopener" title="urllib.request.FancyURLopener"><code class="xref py py-class docutils literal"><span class="pre">FancyURLopener</span></code></a> class offers one additional method that should be
overloaded to provide the appropriate behavior:</p>
<dl class="method">
<dt id="urllib.request.FancyURLopener.prompt_user_passwd">
<code class="descname">prompt_user_passwd</code><span class="sig-paren">(</span><em>host</em>, <em>realm</em><span class="sig-paren">)</span><a class="headerlink" href="#urllib.request.FancyURLopener.prompt_user_passwd" title="Permalink to this definition">¶</a></dt>
<dd><p>Return information needed to authenticate the user at the given host in the
specified security realm.  The return value should be a tuple, <code class="docutils literal"><span class="pre">(user,</span>
<span class="pre">password)</span></code>, which can be used for basic authentication.</p>
<p>The implementation prompts for this information on the terminal; an application
should override this method to use an appropriate interaction model in the local
environment.</p>
</dd></dl>

</dd></dl>

</div>
<div class="section" id="urllib-request-restrictions">
<h2>21.6.25. <a class="reference internal" href="#module-urllib.request" title="urllib.request: Extensible library for opening URLs."><code class="xref py py-mod docutils literal"><span class="pre">urllib.request</span></code></a> Restrictions<a class="headerlink" href="#urllib-request-restrictions" title="Permalink to this headline">¶</a></h2>
<blockquote>
<div></div></blockquote>
<ul id="index-10">
<li><p class="first">Currently, only the following protocols are supported: HTTP (versions 0.9 and
1.0), FTP, local files, and data URLs.</p>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4: </span>Added support for data URLs.</p>
</div>
</li>
<li><p class="first">The caching feature of <a class="reference internal" href="#urllib.request.urlretrieve" title="urllib.request.urlretrieve"><code class="xref py py-func docutils literal"><span class="pre">urlretrieve()</span></code></a> has been disabled until someone
finds the time to hack proper processing of Expiration time headers.</p>
</li>
<li><p class="first">There should be a function to query whether a particular URL is in the cache.</p>
</li>
<li><p class="first">For backward compatibility, if a URL appears to point to a local file but the
file can’t be opened, the URL is re-interpreted using the FTP protocol.  This
can sometimes cause confusing error messages.</p>
</li>
<li><p class="first">The <a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a> and <a class="reference internal" href="#urllib.request.urlretrieve" title="urllib.request.urlretrieve"><code class="xref py py-func docutils literal"><span class="pre">urlretrieve()</span></code></a> functions can cause arbitrarily
long delays while waiting for a network connection to be set up.  This means
that it is difficult to build an interactive Web client using these functions
without using threads.</p>
</li>
<li id="index-11"><p class="first">The data returned by <a class="reference internal" href="#urllib.request.urlopen" title="urllib.request.urlopen"><code class="xref py py-func docutils literal"><span class="pre">urlopen()</span></code></a> or <a class="reference internal" href="#urllib.request.urlretrieve" title="urllib.request.urlretrieve"><code class="xref py py-func docutils literal"><span class="pre">urlretrieve()</span></code></a> is the raw data
returned by the server.  This may be binary data (such as an image), plain text
or (for example) HTML.  The HTTP protocol provides type information in the reply
header, which can be inspected by looking at the <em class="mailheader">Content-Type</em>
header.  If the returned data is HTML, you can use the module
<a class="reference internal" href="html.parser.html#module-html.parser" title="html.parser: A simple parser that can handle HTML and XHTML."><code class="xref py py-mod docutils literal"><span class="pre">html.parser</span></code></a> to parse it.</p>
</li>
<li id="index-12"><p class="first">The code handling the FTP protocol cannot differentiate between a file and a
directory.  This can lead to unexpected behavior when attempting to read a URL
that points to a file that is not accessible.  If the URL ends in a <code class="docutils literal"><span class="pre">/</span></code>, it is
assumed to refer to a directory and will be handled accordingly.  But if an
attempt to read a file leads to a 550 error (meaning the URL cannot be found or
is not accessible, often for permission reasons), then the path is treated as a
directory in order to handle the case when a directory is specified by a URL but
the trailing <code class="docutils literal"><span class="pre">/</span></code> has been left off.  This can cause misleading results when
you try to fetch a file whose read permissions make it inaccessible; the FTP
code will try to read it, fail with a 550 error, and then perform a directory
listing for the unreadable file. If fine-grained control is needed, consider
using the <a class="reference internal" href="ftplib.html#module-ftplib" title="ftplib: FTP protocol client (requires sockets)."><code class="xref py py-mod docutils literal"><span class="pre">ftplib</span></code></a> module, subclassing <a class="reference internal" href="#urllib.request.FancyURLopener" title="urllib.request.FancyURLopener"><code class="xref py py-class docutils literal"><span class="pre">FancyURLopener</span></code></a>, or changing
<em>_urlopener</em> to meet your needs.</p>
</li>
</ul>
</div>
</div>
<div class="section" id="module-urllib.response">
<span id="urllib-response-response-classes-used-by-urllib"></span><h1>21.7. <a class="reference internal" href="#module-urllib.response" title="urllib.response: Response classes used by urllib."><code class="xref py py-mod docutils literal"><span class="pre">urllib.response</span></code></a> — Response classes used by urllib<a class="headerlink" href="#module-urllib.response" title="Permalink to this headline">¶</a></h1>
<p>The <a class="reference internal" href="#module-urllib.response" title="urllib.response: Response classes used by urllib."><code class="xref py py-mod docutils literal"><span class="pre">urllib.response</span></code></a> module defines functions and classes which define a
minimal file like interface, including <code class="docutils literal"><span class="pre">read()</span></code> and <code class="docutils literal"><span class="pre">readline()</span></code>. The
typical response object is an addinfourl instance, which defines an <code class="docutils literal"><span class="pre">info()</span></code>
method and that returns headers and a <code class="docutils literal"><span class="pre">geturl()</span></code> method that returns the url.
Functions defined by this module are used internally by the
<a class="reference internal" href="#module-urllib.request" title="urllib.request: Extensible library for opening URLs."><code class="xref py py-mod docutils literal"><span class="pre">urllib.request</span></code></a> module.</p>
</div>


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  <h3><a href="../contents.html">Table Of Contents</a></h3>
  <ul>
<li><a class="reference internal" href="#">21.6. <code class="docutils literal"><span class="pre">urllib.request</span></code> — Extensible library for opening URLs</a><ul>
<li><a class="reference internal" href="#request-objects">21.6.1. Request Objects</a></li>
<li><a class="reference internal" href="#openerdirector-objects">21.6.2. OpenerDirector Objects</a></li>
<li><a class="reference internal" href="#basehandler-objects">21.6.3. BaseHandler Objects</a></li>
<li><a class="reference internal" href="#httpredirecthandler-objects">21.6.4. HTTPRedirectHandler Objects</a></li>
<li><a class="reference internal" href="#httpcookieprocessor-objects">21.6.5. HTTPCookieProcessor Objects</a></li>
<li><a class="reference internal" href="#proxyhandler-objects">21.6.6. ProxyHandler Objects</a></li>
<li><a class="reference internal" href="#httppasswordmgr-objects">21.6.7. HTTPPasswordMgr Objects</a></li>
<li><a class="reference internal" href="#httppasswordmgrwithpriorauth-objects">21.6.8. HTTPPasswordMgrWithPriorAuth Objects</a></li>
<li><a class="reference internal" href="#abstractbasicauthhandler-objects">21.6.9. AbstractBasicAuthHandler Objects</a></li>
<li><a class="reference internal" href="#httpbasicauthhandler-objects">21.6.10. HTTPBasicAuthHandler Objects</a></li>
<li><a class="reference internal" href="#proxybasicauthhandler-objects">21.6.11. ProxyBasicAuthHandler Objects</a></li>
<li><a class="reference internal" href="#abstractdigestauthhandler-objects">21.6.12. AbstractDigestAuthHandler Objects</a></li>
<li><a class="reference internal" href="#httpdigestauthhandler-objects">21.6.13. HTTPDigestAuthHandler Objects</a></li>
<li><a class="reference internal" href="#proxydigestauthhandler-objects">21.6.14. ProxyDigestAuthHandler Objects</a></li>
<li><a class="reference internal" href="#httphandler-objects">21.6.15. HTTPHandler Objects</a></li>
<li><a class="reference internal" href="#httpshandler-objects">21.6.16. HTTPSHandler Objects</a></li>
<li><a class="reference internal" href="#filehandler-objects">21.6.17. FileHandler Objects</a></li>
<li><a class="reference internal" href="#datahandler-objects">21.6.18. DataHandler Objects</a></li>
<li><a class="reference internal" href="#ftphandler-objects">21.6.19. FTPHandler Objects</a></li>
<li><a class="reference internal" href="#cacheftphandler-objects">21.6.20. CacheFTPHandler Objects</a></li>
<li><a class="reference internal" href="#unknownhandler-objects">21.6.21. UnknownHandler Objects</a></li>
<li><a class="reference internal" href="#httperrorprocessor-objects">21.6.22. HTTPErrorProcessor Objects</a></li>
<li><a class="reference internal" href="#examples">21.6.23. Examples</a></li>
<li><a class="reference internal" href="#legacy-interface">21.6.24. Legacy interface</a></li>
<li><a class="reference internal" href="#urllib-request-restrictions">21.6.25. <code class="docutils literal"><span class="pre">urllib.request</span></code> Restrictions</a></li>
</ul>
</li>
<li><a class="reference internal" href="#module-urllib.response">21.7. <code class="docutils literal"><span class="pre">urllib.response</span></code> — Response classes used by urllib</a></li>
</ul>

  <h4>Previous topic</h4>
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